Download - R.Carlin 2006 Aspen Winter Conference HERA for LHC Roberto Carlin University of Padova and INFN-PD
RCarlin 2006 Aspen Winter Conference
HERA for LHC
Roberto CarlinUniversity of
Padova and INFN-PD
RCarlin 2006 Aspen Winter Conference
LHC pp collider radics = 14 TeV
Discovery machine Higgs Susy
But it is a parton-parton colliderneed the structure of the proton and QCD to get precise results understand the backgrounds to new physics measure the luminosity
Need to control QCD effects at the best
RCarlin 2006 Aspen Winter Conference
HERA ep collider radics = 320 GeV
Mostly a QCD machine
Parton densities jets hard diffraction heavy flavors productionhellipThe photon can be used as an hadronic probe (ldquoresolvedrdquo photon in photoproduction) multiple intraction gap survival in diffractionhellip
HERA is the ideal machine to make precision QCD studies and test new QCD predictions
RCarlin 2006 Aspen Winter Conference
Topics for this talkbull What is the impact of
the measurements done so far (HERA-I)
bull Can we do better in HERA-II for what concernes LHC
bull What should be measured really to have an impact
bull Structure functions and parton distribution functions
bull Diffraction diffractive PDFs and generalised parton distributions
bull Multiple interactionsbull Heavy flavor
production
Very detailed documentation in the proceedings of the HERA-LHC workshop recently issued as CERN-2005-014 yellow reportApologies to the original authors for the plots without the proper reference
RCarlin 2006 Aspen Winter Conference
Parton distributions HERA results
PDFs fits without and with HERA data at different Q2 uncertainty vastly reduced particularly at low-x NB same fit sameparametrization and DGLAP evolution just no HERA data
RCarlin 2006 Aspen Winter Conference
Example the effect of HERA PDFs in the determination of the W+ production at LHC
Process is important for the measurement of the luminosity in LHC
00001ltxlt01
bull Uncertainty from a specific PDF fit goes from ~16 to ~35 using HERA data
bull Low- to midle-x gluon knowledge is essential
bull Is our knowledge of PDFsit good enough
W+ rapidity
W+ rapidity
RCarlin 2006 Aspen Winter Conference
Results of H1 and ZEUS are compatible
But there are clear differences particularly at low-x in the gluon The differences are mostly from the dat sets not from the fits and prameterizations
NB the gluon is not directly measured in HERA enters in the PDFs from F2lnQ2
use exclusive measurements senitive to the gluons (jets charmhellip)
Example of differences between PDFs
RCarlin 2006 Aspen Winter Conference
bullSpread of existing PDFs gives 10 uncertainty on Higgs cross sections at LHC
bullSame in the W production (8)bullNeed to do better than this
Djouadi amp Ferrag
RCarlin 2006 Aspen Winter Conference
Not only experimental data but also QCD calculations need progress (NNLOhellip) for the PDF fits
Large evolution from HERA to LHC to high-Q2 and low-x
bull Is NLO (NNLO) DGLAP good enough
bull Collinear factorization kt effects
bull BFKL ln(1x) resummationbull Saturation non linear
evolution
Precise data from HERA should help models to disentangle these effects
RCarlin 2006 Aspen Winter Conference
HERA-2 is expecting an integrated luminosity ~700pb-1 (H1 and ZEUS have ~130pb-1 on tape from HERA-1) Various improvements are possible
bull Use Jet data in the fits with higher statistics
bull Increased statistics on high Q2 data
bull Measure FL
Improvements are also possible with present data
bull Improved systematicsbull Combined data fits
How can we improve with HERA-2 the uncertainty in the PDFs
RCarlin 2006 Aspen Winter Conference
Improves the mid- to high-x gluon distributions up to high scalesAllowes to fit without the low energy heavy target data (target corrections systematics)
The use of high statitics HERA-2 data brings a significative improvement
gluon fractional errorInclusion of DIS Jet and High-Et dijet photoproduction data in the PDFs fits
Even better using full statistics AND optimised jet cross sectionsmeasurements designed to optimise the sensitivity to the gluon density
C Gwenlan A Cooper-Sarkar CTargett-Adams
RCarlin 2006 Aspen Winter Conference
At high-Q2 high-x the NCCC measurement is still limited by statistics
Expect impact in the valence quarks distributions
The measurements at low-Q2 are already limited by the systematic uncertainties O(2-3)
bullH1 is planning to reduce the systematics at low-Q2 using HERA-I yr 2000 databullGoal is to reach 1 level will effect mostly low-x gluon
RCarlin 2006 Aspen Winter Conference
Simulation 500 pb-1 in the e+ and e- channels
Improvement up to a factor 2 in the valence
NB this is a ZEUS fit with jets cross sections and no low energy data results still improves wrt global fits
There are also improvements in xF3~Σ(q-qbar) up to a factor of three
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (I)
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (II)
Uncertainty on jet cross section at LHC significantly reduced
RCarlin 2006 Aspen Winter Conference
Measurement of FL
Can be performed with a set of lowered p energies at HERA-2 (~10pb-1)
bull σr~F2(xQ2)-f(y)FL(xQ2) y=Q2sxbull measure cross sections at high-y and change y at fixed xQ2
(change s)
FL~sxg(xQ2)
direct measurement of the gluon
M Klein
RCarlin 2006 Aspen Winter Conference
Result of a simulation (MKlein)
bull Can get ΔFL ~ 10-20bull The measurement of FL can
have an impact mostly in the low-x gluon low-Q
bull Important test of QCD consistency
bull HERA is the only place to mesure it
bull Trade off with luminosity lost at high energy
bull Luminosity goes as Ep2
bull Setup the machinebull Problem are the present
detectors well tuned to the measurement (low-x low-Q2)
RCarlin 2006 Aspen Winter Conference
Overall improvement from HERA-II statistics
RCarlin 2006 Aspen Winter Conference
Combining H1 and ZEUS present data
Using H1 and ZEUS data together in standard QCD fits The improvement is marginal errors are dominated by systematics the data sets are not incompatible but pull against each otherhellip
RCarlin 2006 Aspen Winter Conference
Example on how the combined ldquoHERArdquo data set after the fit is betterthan each individual pointBeware still preliminary all pitfalls have to be worked out
Different method (Glazov) Global (Hessian) fit of H1 and ZEUS cross section data The idea is that we are measuring the same thing and the systematics of one experiment can be solved by the other taking into account correlations Indeed systematics are quite different between ZEUS and H1
It is a duty of the HERA community to provide the best PDFs
RCarlin 2006 Aspen Winter Conference
Diffractive Higgs production at LHC
2-10 fb
bullClean signal very good mass resolution for the exclusive process
bullNeed knowledge of the diffractive PDFs and GPD
O(100) fb
fi(zXIPtQ2)
RCarlin 2006 Aspen Winter Conference
HERA is measuring DVCS and eleastic VM production (ρφJΨ Υ)
which are in principle sensitive to GPDsbullVM data sensitive to gluon distribution at x~(MV
2+Q2)W2
(neglecting skeweness of the two gluons)
RCarlin 2006 Aspen Winter Conference
Example exclusive JΨ production in DISbullSmallest theoretical error in DVCS and ΥbullRates are low need HERA-2
RCarlin 2006 Aspen Winter Conference
Diffraction at HERA
bull ~10 of DIS NC events are diffractive (rapidity gap)
bull Hard process should be described by QCD (2g exchange)
bull QCD factorization a hard process and a structure function F2
D(4)(xIPtβQ2)
bull Measure the diffractive PDFsbullBackground to the exclusive diffraction at LH
bull Understand the gap survival probability
X
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
LHC pp collider radics = 14 TeV
Discovery machine Higgs Susy
But it is a parton-parton colliderneed the structure of the proton and QCD to get precise results understand the backgrounds to new physics measure the luminosity
Need to control QCD effects at the best
RCarlin 2006 Aspen Winter Conference
HERA ep collider radics = 320 GeV
Mostly a QCD machine
Parton densities jets hard diffraction heavy flavors productionhellipThe photon can be used as an hadronic probe (ldquoresolvedrdquo photon in photoproduction) multiple intraction gap survival in diffractionhellip
HERA is the ideal machine to make precision QCD studies and test new QCD predictions
RCarlin 2006 Aspen Winter Conference
Topics for this talkbull What is the impact of
the measurements done so far (HERA-I)
bull Can we do better in HERA-II for what concernes LHC
bull What should be measured really to have an impact
bull Structure functions and parton distribution functions
bull Diffraction diffractive PDFs and generalised parton distributions
bull Multiple interactionsbull Heavy flavor
production
Very detailed documentation in the proceedings of the HERA-LHC workshop recently issued as CERN-2005-014 yellow reportApologies to the original authors for the plots without the proper reference
RCarlin 2006 Aspen Winter Conference
Parton distributions HERA results
PDFs fits without and with HERA data at different Q2 uncertainty vastly reduced particularly at low-x NB same fit sameparametrization and DGLAP evolution just no HERA data
RCarlin 2006 Aspen Winter Conference
Example the effect of HERA PDFs in the determination of the W+ production at LHC
Process is important for the measurement of the luminosity in LHC
00001ltxlt01
bull Uncertainty from a specific PDF fit goes from ~16 to ~35 using HERA data
bull Low- to midle-x gluon knowledge is essential
bull Is our knowledge of PDFsit good enough
W+ rapidity
W+ rapidity
RCarlin 2006 Aspen Winter Conference
Results of H1 and ZEUS are compatible
But there are clear differences particularly at low-x in the gluon The differences are mostly from the dat sets not from the fits and prameterizations
NB the gluon is not directly measured in HERA enters in the PDFs from F2lnQ2
use exclusive measurements senitive to the gluons (jets charmhellip)
Example of differences between PDFs
RCarlin 2006 Aspen Winter Conference
bullSpread of existing PDFs gives 10 uncertainty on Higgs cross sections at LHC
bullSame in the W production (8)bullNeed to do better than this
Djouadi amp Ferrag
RCarlin 2006 Aspen Winter Conference
Not only experimental data but also QCD calculations need progress (NNLOhellip) for the PDF fits
Large evolution from HERA to LHC to high-Q2 and low-x
bull Is NLO (NNLO) DGLAP good enough
bull Collinear factorization kt effects
bull BFKL ln(1x) resummationbull Saturation non linear
evolution
Precise data from HERA should help models to disentangle these effects
RCarlin 2006 Aspen Winter Conference
HERA-2 is expecting an integrated luminosity ~700pb-1 (H1 and ZEUS have ~130pb-1 on tape from HERA-1) Various improvements are possible
bull Use Jet data in the fits with higher statistics
bull Increased statistics on high Q2 data
bull Measure FL
Improvements are also possible with present data
bull Improved systematicsbull Combined data fits
How can we improve with HERA-2 the uncertainty in the PDFs
RCarlin 2006 Aspen Winter Conference
Improves the mid- to high-x gluon distributions up to high scalesAllowes to fit without the low energy heavy target data (target corrections systematics)
The use of high statitics HERA-2 data brings a significative improvement
gluon fractional errorInclusion of DIS Jet and High-Et dijet photoproduction data in the PDFs fits
Even better using full statistics AND optimised jet cross sectionsmeasurements designed to optimise the sensitivity to the gluon density
C Gwenlan A Cooper-Sarkar CTargett-Adams
RCarlin 2006 Aspen Winter Conference
At high-Q2 high-x the NCCC measurement is still limited by statistics
Expect impact in the valence quarks distributions
The measurements at low-Q2 are already limited by the systematic uncertainties O(2-3)
bullH1 is planning to reduce the systematics at low-Q2 using HERA-I yr 2000 databullGoal is to reach 1 level will effect mostly low-x gluon
RCarlin 2006 Aspen Winter Conference
Simulation 500 pb-1 in the e+ and e- channels
Improvement up to a factor 2 in the valence
NB this is a ZEUS fit with jets cross sections and no low energy data results still improves wrt global fits
There are also improvements in xF3~Σ(q-qbar) up to a factor of three
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (I)
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (II)
Uncertainty on jet cross section at LHC significantly reduced
RCarlin 2006 Aspen Winter Conference
Measurement of FL
Can be performed with a set of lowered p energies at HERA-2 (~10pb-1)
bull σr~F2(xQ2)-f(y)FL(xQ2) y=Q2sxbull measure cross sections at high-y and change y at fixed xQ2
(change s)
FL~sxg(xQ2)
direct measurement of the gluon
M Klein
RCarlin 2006 Aspen Winter Conference
Result of a simulation (MKlein)
bull Can get ΔFL ~ 10-20bull The measurement of FL can
have an impact mostly in the low-x gluon low-Q
bull Important test of QCD consistency
bull HERA is the only place to mesure it
bull Trade off with luminosity lost at high energy
bull Luminosity goes as Ep2
bull Setup the machinebull Problem are the present
detectors well tuned to the measurement (low-x low-Q2)
RCarlin 2006 Aspen Winter Conference
Overall improvement from HERA-II statistics
RCarlin 2006 Aspen Winter Conference
Combining H1 and ZEUS present data
Using H1 and ZEUS data together in standard QCD fits The improvement is marginal errors are dominated by systematics the data sets are not incompatible but pull against each otherhellip
RCarlin 2006 Aspen Winter Conference
Example on how the combined ldquoHERArdquo data set after the fit is betterthan each individual pointBeware still preliminary all pitfalls have to be worked out
Different method (Glazov) Global (Hessian) fit of H1 and ZEUS cross section data The idea is that we are measuring the same thing and the systematics of one experiment can be solved by the other taking into account correlations Indeed systematics are quite different between ZEUS and H1
It is a duty of the HERA community to provide the best PDFs
RCarlin 2006 Aspen Winter Conference
Diffractive Higgs production at LHC
2-10 fb
bullClean signal very good mass resolution for the exclusive process
bullNeed knowledge of the diffractive PDFs and GPD
O(100) fb
fi(zXIPtQ2)
RCarlin 2006 Aspen Winter Conference
HERA is measuring DVCS and eleastic VM production (ρφJΨ Υ)
which are in principle sensitive to GPDsbullVM data sensitive to gluon distribution at x~(MV
2+Q2)W2
(neglecting skeweness of the two gluons)
RCarlin 2006 Aspen Winter Conference
Example exclusive JΨ production in DISbullSmallest theoretical error in DVCS and ΥbullRates are low need HERA-2
RCarlin 2006 Aspen Winter Conference
Diffraction at HERA
bull ~10 of DIS NC events are diffractive (rapidity gap)
bull Hard process should be described by QCD (2g exchange)
bull QCD factorization a hard process and a structure function F2
D(4)(xIPtβQ2)
bull Measure the diffractive PDFsbullBackground to the exclusive diffraction at LH
bull Understand the gap survival probability
X
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
HERA ep collider radics = 320 GeV
Mostly a QCD machine
Parton densities jets hard diffraction heavy flavors productionhellipThe photon can be used as an hadronic probe (ldquoresolvedrdquo photon in photoproduction) multiple intraction gap survival in diffractionhellip
HERA is the ideal machine to make precision QCD studies and test new QCD predictions
RCarlin 2006 Aspen Winter Conference
Topics for this talkbull What is the impact of
the measurements done so far (HERA-I)
bull Can we do better in HERA-II for what concernes LHC
bull What should be measured really to have an impact
bull Structure functions and parton distribution functions
bull Diffraction diffractive PDFs and generalised parton distributions
bull Multiple interactionsbull Heavy flavor
production
Very detailed documentation in the proceedings of the HERA-LHC workshop recently issued as CERN-2005-014 yellow reportApologies to the original authors for the plots without the proper reference
RCarlin 2006 Aspen Winter Conference
Parton distributions HERA results
PDFs fits without and with HERA data at different Q2 uncertainty vastly reduced particularly at low-x NB same fit sameparametrization and DGLAP evolution just no HERA data
RCarlin 2006 Aspen Winter Conference
Example the effect of HERA PDFs in the determination of the W+ production at LHC
Process is important for the measurement of the luminosity in LHC
00001ltxlt01
bull Uncertainty from a specific PDF fit goes from ~16 to ~35 using HERA data
bull Low- to midle-x gluon knowledge is essential
bull Is our knowledge of PDFsit good enough
W+ rapidity
W+ rapidity
RCarlin 2006 Aspen Winter Conference
Results of H1 and ZEUS are compatible
But there are clear differences particularly at low-x in the gluon The differences are mostly from the dat sets not from the fits and prameterizations
NB the gluon is not directly measured in HERA enters in the PDFs from F2lnQ2
use exclusive measurements senitive to the gluons (jets charmhellip)
Example of differences between PDFs
RCarlin 2006 Aspen Winter Conference
bullSpread of existing PDFs gives 10 uncertainty on Higgs cross sections at LHC
bullSame in the W production (8)bullNeed to do better than this
Djouadi amp Ferrag
RCarlin 2006 Aspen Winter Conference
Not only experimental data but also QCD calculations need progress (NNLOhellip) for the PDF fits
Large evolution from HERA to LHC to high-Q2 and low-x
bull Is NLO (NNLO) DGLAP good enough
bull Collinear factorization kt effects
bull BFKL ln(1x) resummationbull Saturation non linear
evolution
Precise data from HERA should help models to disentangle these effects
RCarlin 2006 Aspen Winter Conference
HERA-2 is expecting an integrated luminosity ~700pb-1 (H1 and ZEUS have ~130pb-1 on tape from HERA-1) Various improvements are possible
bull Use Jet data in the fits with higher statistics
bull Increased statistics on high Q2 data
bull Measure FL
Improvements are also possible with present data
bull Improved systematicsbull Combined data fits
How can we improve with HERA-2 the uncertainty in the PDFs
RCarlin 2006 Aspen Winter Conference
Improves the mid- to high-x gluon distributions up to high scalesAllowes to fit without the low energy heavy target data (target corrections systematics)
The use of high statitics HERA-2 data brings a significative improvement
gluon fractional errorInclusion of DIS Jet and High-Et dijet photoproduction data in the PDFs fits
Even better using full statistics AND optimised jet cross sectionsmeasurements designed to optimise the sensitivity to the gluon density
C Gwenlan A Cooper-Sarkar CTargett-Adams
RCarlin 2006 Aspen Winter Conference
At high-Q2 high-x the NCCC measurement is still limited by statistics
Expect impact in the valence quarks distributions
The measurements at low-Q2 are already limited by the systematic uncertainties O(2-3)
bullH1 is planning to reduce the systematics at low-Q2 using HERA-I yr 2000 databullGoal is to reach 1 level will effect mostly low-x gluon
RCarlin 2006 Aspen Winter Conference
Simulation 500 pb-1 in the e+ and e- channels
Improvement up to a factor 2 in the valence
NB this is a ZEUS fit with jets cross sections and no low energy data results still improves wrt global fits
There are also improvements in xF3~Σ(q-qbar) up to a factor of three
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (I)
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (II)
Uncertainty on jet cross section at LHC significantly reduced
RCarlin 2006 Aspen Winter Conference
Measurement of FL
Can be performed with a set of lowered p energies at HERA-2 (~10pb-1)
bull σr~F2(xQ2)-f(y)FL(xQ2) y=Q2sxbull measure cross sections at high-y and change y at fixed xQ2
(change s)
FL~sxg(xQ2)
direct measurement of the gluon
M Klein
RCarlin 2006 Aspen Winter Conference
Result of a simulation (MKlein)
bull Can get ΔFL ~ 10-20bull The measurement of FL can
have an impact mostly in the low-x gluon low-Q
bull Important test of QCD consistency
bull HERA is the only place to mesure it
bull Trade off with luminosity lost at high energy
bull Luminosity goes as Ep2
bull Setup the machinebull Problem are the present
detectors well tuned to the measurement (low-x low-Q2)
RCarlin 2006 Aspen Winter Conference
Overall improvement from HERA-II statistics
RCarlin 2006 Aspen Winter Conference
Combining H1 and ZEUS present data
Using H1 and ZEUS data together in standard QCD fits The improvement is marginal errors are dominated by systematics the data sets are not incompatible but pull against each otherhellip
RCarlin 2006 Aspen Winter Conference
Example on how the combined ldquoHERArdquo data set after the fit is betterthan each individual pointBeware still preliminary all pitfalls have to be worked out
Different method (Glazov) Global (Hessian) fit of H1 and ZEUS cross section data The idea is that we are measuring the same thing and the systematics of one experiment can be solved by the other taking into account correlations Indeed systematics are quite different between ZEUS and H1
It is a duty of the HERA community to provide the best PDFs
RCarlin 2006 Aspen Winter Conference
Diffractive Higgs production at LHC
2-10 fb
bullClean signal very good mass resolution for the exclusive process
bullNeed knowledge of the diffractive PDFs and GPD
O(100) fb
fi(zXIPtQ2)
RCarlin 2006 Aspen Winter Conference
HERA is measuring DVCS and eleastic VM production (ρφJΨ Υ)
which are in principle sensitive to GPDsbullVM data sensitive to gluon distribution at x~(MV
2+Q2)W2
(neglecting skeweness of the two gluons)
RCarlin 2006 Aspen Winter Conference
Example exclusive JΨ production in DISbullSmallest theoretical error in DVCS and ΥbullRates are low need HERA-2
RCarlin 2006 Aspen Winter Conference
Diffraction at HERA
bull ~10 of DIS NC events are diffractive (rapidity gap)
bull Hard process should be described by QCD (2g exchange)
bull QCD factorization a hard process and a structure function F2
D(4)(xIPtβQ2)
bull Measure the diffractive PDFsbullBackground to the exclusive diffraction at LH
bull Understand the gap survival probability
X
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
Topics for this talkbull What is the impact of
the measurements done so far (HERA-I)
bull Can we do better in HERA-II for what concernes LHC
bull What should be measured really to have an impact
bull Structure functions and parton distribution functions
bull Diffraction diffractive PDFs and generalised parton distributions
bull Multiple interactionsbull Heavy flavor
production
Very detailed documentation in the proceedings of the HERA-LHC workshop recently issued as CERN-2005-014 yellow reportApologies to the original authors for the plots without the proper reference
RCarlin 2006 Aspen Winter Conference
Parton distributions HERA results
PDFs fits without and with HERA data at different Q2 uncertainty vastly reduced particularly at low-x NB same fit sameparametrization and DGLAP evolution just no HERA data
RCarlin 2006 Aspen Winter Conference
Example the effect of HERA PDFs in the determination of the W+ production at LHC
Process is important for the measurement of the luminosity in LHC
00001ltxlt01
bull Uncertainty from a specific PDF fit goes from ~16 to ~35 using HERA data
bull Low- to midle-x gluon knowledge is essential
bull Is our knowledge of PDFsit good enough
W+ rapidity
W+ rapidity
RCarlin 2006 Aspen Winter Conference
Results of H1 and ZEUS are compatible
But there are clear differences particularly at low-x in the gluon The differences are mostly from the dat sets not from the fits and prameterizations
NB the gluon is not directly measured in HERA enters in the PDFs from F2lnQ2
use exclusive measurements senitive to the gluons (jets charmhellip)
Example of differences between PDFs
RCarlin 2006 Aspen Winter Conference
bullSpread of existing PDFs gives 10 uncertainty on Higgs cross sections at LHC
bullSame in the W production (8)bullNeed to do better than this
Djouadi amp Ferrag
RCarlin 2006 Aspen Winter Conference
Not only experimental data but also QCD calculations need progress (NNLOhellip) for the PDF fits
Large evolution from HERA to LHC to high-Q2 and low-x
bull Is NLO (NNLO) DGLAP good enough
bull Collinear factorization kt effects
bull BFKL ln(1x) resummationbull Saturation non linear
evolution
Precise data from HERA should help models to disentangle these effects
RCarlin 2006 Aspen Winter Conference
HERA-2 is expecting an integrated luminosity ~700pb-1 (H1 and ZEUS have ~130pb-1 on tape from HERA-1) Various improvements are possible
bull Use Jet data in the fits with higher statistics
bull Increased statistics on high Q2 data
bull Measure FL
Improvements are also possible with present data
bull Improved systematicsbull Combined data fits
How can we improve with HERA-2 the uncertainty in the PDFs
RCarlin 2006 Aspen Winter Conference
Improves the mid- to high-x gluon distributions up to high scalesAllowes to fit without the low energy heavy target data (target corrections systematics)
The use of high statitics HERA-2 data brings a significative improvement
gluon fractional errorInclusion of DIS Jet and High-Et dijet photoproduction data in the PDFs fits
Even better using full statistics AND optimised jet cross sectionsmeasurements designed to optimise the sensitivity to the gluon density
C Gwenlan A Cooper-Sarkar CTargett-Adams
RCarlin 2006 Aspen Winter Conference
At high-Q2 high-x the NCCC measurement is still limited by statistics
Expect impact in the valence quarks distributions
The measurements at low-Q2 are already limited by the systematic uncertainties O(2-3)
bullH1 is planning to reduce the systematics at low-Q2 using HERA-I yr 2000 databullGoal is to reach 1 level will effect mostly low-x gluon
RCarlin 2006 Aspen Winter Conference
Simulation 500 pb-1 in the e+ and e- channels
Improvement up to a factor 2 in the valence
NB this is a ZEUS fit with jets cross sections and no low energy data results still improves wrt global fits
There are also improvements in xF3~Σ(q-qbar) up to a factor of three
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (I)
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (II)
Uncertainty on jet cross section at LHC significantly reduced
RCarlin 2006 Aspen Winter Conference
Measurement of FL
Can be performed with a set of lowered p energies at HERA-2 (~10pb-1)
bull σr~F2(xQ2)-f(y)FL(xQ2) y=Q2sxbull measure cross sections at high-y and change y at fixed xQ2
(change s)
FL~sxg(xQ2)
direct measurement of the gluon
M Klein
RCarlin 2006 Aspen Winter Conference
Result of a simulation (MKlein)
bull Can get ΔFL ~ 10-20bull The measurement of FL can
have an impact mostly in the low-x gluon low-Q
bull Important test of QCD consistency
bull HERA is the only place to mesure it
bull Trade off with luminosity lost at high energy
bull Luminosity goes as Ep2
bull Setup the machinebull Problem are the present
detectors well tuned to the measurement (low-x low-Q2)
RCarlin 2006 Aspen Winter Conference
Overall improvement from HERA-II statistics
RCarlin 2006 Aspen Winter Conference
Combining H1 and ZEUS present data
Using H1 and ZEUS data together in standard QCD fits The improvement is marginal errors are dominated by systematics the data sets are not incompatible but pull against each otherhellip
RCarlin 2006 Aspen Winter Conference
Example on how the combined ldquoHERArdquo data set after the fit is betterthan each individual pointBeware still preliminary all pitfalls have to be worked out
Different method (Glazov) Global (Hessian) fit of H1 and ZEUS cross section data The idea is that we are measuring the same thing and the systematics of one experiment can be solved by the other taking into account correlations Indeed systematics are quite different between ZEUS and H1
It is a duty of the HERA community to provide the best PDFs
RCarlin 2006 Aspen Winter Conference
Diffractive Higgs production at LHC
2-10 fb
bullClean signal very good mass resolution for the exclusive process
bullNeed knowledge of the diffractive PDFs and GPD
O(100) fb
fi(zXIPtQ2)
RCarlin 2006 Aspen Winter Conference
HERA is measuring DVCS and eleastic VM production (ρφJΨ Υ)
which are in principle sensitive to GPDsbullVM data sensitive to gluon distribution at x~(MV
2+Q2)W2
(neglecting skeweness of the two gluons)
RCarlin 2006 Aspen Winter Conference
Example exclusive JΨ production in DISbullSmallest theoretical error in DVCS and ΥbullRates are low need HERA-2
RCarlin 2006 Aspen Winter Conference
Diffraction at HERA
bull ~10 of DIS NC events are diffractive (rapidity gap)
bull Hard process should be described by QCD (2g exchange)
bull QCD factorization a hard process and a structure function F2
D(4)(xIPtβQ2)
bull Measure the diffractive PDFsbullBackground to the exclusive diffraction at LH
bull Understand the gap survival probability
X
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
Parton distributions HERA results
PDFs fits without and with HERA data at different Q2 uncertainty vastly reduced particularly at low-x NB same fit sameparametrization and DGLAP evolution just no HERA data
RCarlin 2006 Aspen Winter Conference
Example the effect of HERA PDFs in the determination of the W+ production at LHC
Process is important for the measurement of the luminosity in LHC
00001ltxlt01
bull Uncertainty from a specific PDF fit goes from ~16 to ~35 using HERA data
bull Low- to midle-x gluon knowledge is essential
bull Is our knowledge of PDFsit good enough
W+ rapidity
W+ rapidity
RCarlin 2006 Aspen Winter Conference
Results of H1 and ZEUS are compatible
But there are clear differences particularly at low-x in the gluon The differences are mostly from the dat sets not from the fits and prameterizations
NB the gluon is not directly measured in HERA enters in the PDFs from F2lnQ2
use exclusive measurements senitive to the gluons (jets charmhellip)
Example of differences between PDFs
RCarlin 2006 Aspen Winter Conference
bullSpread of existing PDFs gives 10 uncertainty on Higgs cross sections at LHC
bullSame in the W production (8)bullNeed to do better than this
Djouadi amp Ferrag
RCarlin 2006 Aspen Winter Conference
Not only experimental data but also QCD calculations need progress (NNLOhellip) for the PDF fits
Large evolution from HERA to LHC to high-Q2 and low-x
bull Is NLO (NNLO) DGLAP good enough
bull Collinear factorization kt effects
bull BFKL ln(1x) resummationbull Saturation non linear
evolution
Precise data from HERA should help models to disentangle these effects
RCarlin 2006 Aspen Winter Conference
HERA-2 is expecting an integrated luminosity ~700pb-1 (H1 and ZEUS have ~130pb-1 on tape from HERA-1) Various improvements are possible
bull Use Jet data in the fits with higher statistics
bull Increased statistics on high Q2 data
bull Measure FL
Improvements are also possible with present data
bull Improved systematicsbull Combined data fits
How can we improve with HERA-2 the uncertainty in the PDFs
RCarlin 2006 Aspen Winter Conference
Improves the mid- to high-x gluon distributions up to high scalesAllowes to fit without the low energy heavy target data (target corrections systematics)
The use of high statitics HERA-2 data brings a significative improvement
gluon fractional errorInclusion of DIS Jet and High-Et dijet photoproduction data in the PDFs fits
Even better using full statistics AND optimised jet cross sectionsmeasurements designed to optimise the sensitivity to the gluon density
C Gwenlan A Cooper-Sarkar CTargett-Adams
RCarlin 2006 Aspen Winter Conference
At high-Q2 high-x the NCCC measurement is still limited by statistics
Expect impact in the valence quarks distributions
The measurements at low-Q2 are already limited by the systematic uncertainties O(2-3)
bullH1 is planning to reduce the systematics at low-Q2 using HERA-I yr 2000 databullGoal is to reach 1 level will effect mostly low-x gluon
RCarlin 2006 Aspen Winter Conference
Simulation 500 pb-1 in the e+ and e- channels
Improvement up to a factor 2 in the valence
NB this is a ZEUS fit with jets cross sections and no low energy data results still improves wrt global fits
There are also improvements in xF3~Σ(q-qbar) up to a factor of three
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (I)
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (II)
Uncertainty on jet cross section at LHC significantly reduced
RCarlin 2006 Aspen Winter Conference
Measurement of FL
Can be performed with a set of lowered p energies at HERA-2 (~10pb-1)
bull σr~F2(xQ2)-f(y)FL(xQ2) y=Q2sxbull measure cross sections at high-y and change y at fixed xQ2
(change s)
FL~sxg(xQ2)
direct measurement of the gluon
M Klein
RCarlin 2006 Aspen Winter Conference
Result of a simulation (MKlein)
bull Can get ΔFL ~ 10-20bull The measurement of FL can
have an impact mostly in the low-x gluon low-Q
bull Important test of QCD consistency
bull HERA is the only place to mesure it
bull Trade off with luminosity lost at high energy
bull Luminosity goes as Ep2
bull Setup the machinebull Problem are the present
detectors well tuned to the measurement (low-x low-Q2)
RCarlin 2006 Aspen Winter Conference
Overall improvement from HERA-II statistics
RCarlin 2006 Aspen Winter Conference
Combining H1 and ZEUS present data
Using H1 and ZEUS data together in standard QCD fits The improvement is marginal errors are dominated by systematics the data sets are not incompatible but pull against each otherhellip
RCarlin 2006 Aspen Winter Conference
Example on how the combined ldquoHERArdquo data set after the fit is betterthan each individual pointBeware still preliminary all pitfalls have to be worked out
Different method (Glazov) Global (Hessian) fit of H1 and ZEUS cross section data The idea is that we are measuring the same thing and the systematics of one experiment can be solved by the other taking into account correlations Indeed systematics are quite different between ZEUS and H1
It is a duty of the HERA community to provide the best PDFs
RCarlin 2006 Aspen Winter Conference
Diffractive Higgs production at LHC
2-10 fb
bullClean signal very good mass resolution for the exclusive process
bullNeed knowledge of the diffractive PDFs and GPD
O(100) fb
fi(zXIPtQ2)
RCarlin 2006 Aspen Winter Conference
HERA is measuring DVCS and eleastic VM production (ρφJΨ Υ)
which are in principle sensitive to GPDsbullVM data sensitive to gluon distribution at x~(MV
2+Q2)W2
(neglecting skeweness of the two gluons)
RCarlin 2006 Aspen Winter Conference
Example exclusive JΨ production in DISbullSmallest theoretical error in DVCS and ΥbullRates are low need HERA-2
RCarlin 2006 Aspen Winter Conference
Diffraction at HERA
bull ~10 of DIS NC events are diffractive (rapidity gap)
bull Hard process should be described by QCD (2g exchange)
bull QCD factorization a hard process and a structure function F2
D(4)(xIPtβQ2)
bull Measure the diffractive PDFsbullBackground to the exclusive diffraction at LH
bull Understand the gap survival probability
X
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
Example the effect of HERA PDFs in the determination of the W+ production at LHC
Process is important for the measurement of the luminosity in LHC
00001ltxlt01
bull Uncertainty from a specific PDF fit goes from ~16 to ~35 using HERA data
bull Low- to midle-x gluon knowledge is essential
bull Is our knowledge of PDFsit good enough
W+ rapidity
W+ rapidity
RCarlin 2006 Aspen Winter Conference
Results of H1 and ZEUS are compatible
But there are clear differences particularly at low-x in the gluon The differences are mostly from the dat sets not from the fits and prameterizations
NB the gluon is not directly measured in HERA enters in the PDFs from F2lnQ2
use exclusive measurements senitive to the gluons (jets charmhellip)
Example of differences between PDFs
RCarlin 2006 Aspen Winter Conference
bullSpread of existing PDFs gives 10 uncertainty on Higgs cross sections at LHC
bullSame in the W production (8)bullNeed to do better than this
Djouadi amp Ferrag
RCarlin 2006 Aspen Winter Conference
Not only experimental data but also QCD calculations need progress (NNLOhellip) for the PDF fits
Large evolution from HERA to LHC to high-Q2 and low-x
bull Is NLO (NNLO) DGLAP good enough
bull Collinear factorization kt effects
bull BFKL ln(1x) resummationbull Saturation non linear
evolution
Precise data from HERA should help models to disentangle these effects
RCarlin 2006 Aspen Winter Conference
HERA-2 is expecting an integrated luminosity ~700pb-1 (H1 and ZEUS have ~130pb-1 on tape from HERA-1) Various improvements are possible
bull Use Jet data in the fits with higher statistics
bull Increased statistics on high Q2 data
bull Measure FL
Improvements are also possible with present data
bull Improved systematicsbull Combined data fits
How can we improve with HERA-2 the uncertainty in the PDFs
RCarlin 2006 Aspen Winter Conference
Improves the mid- to high-x gluon distributions up to high scalesAllowes to fit without the low energy heavy target data (target corrections systematics)
The use of high statitics HERA-2 data brings a significative improvement
gluon fractional errorInclusion of DIS Jet and High-Et dijet photoproduction data in the PDFs fits
Even better using full statistics AND optimised jet cross sectionsmeasurements designed to optimise the sensitivity to the gluon density
C Gwenlan A Cooper-Sarkar CTargett-Adams
RCarlin 2006 Aspen Winter Conference
At high-Q2 high-x the NCCC measurement is still limited by statistics
Expect impact in the valence quarks distributions
The measurements at low-Q2 are already limited by the systematic uncertainties O(2-3)
bullH1 is planning to reduce the systematics at low-Q2 using HERA-I yr 2000 databullGoal is to reach 1 level will effect mostly low-x gluon
RCarlin 2006 Aspen Winter Conference
Simulation 500 pb-1 in the e+ and e- channels
Improvement up to a factor 2 in the valence
NB this is a ZEUS fit with jets cross sections and no low energy data results still improves wrt global fits
There are also improvements in xF3~Σ(q-qbar) up to a factor of three
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (I)
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (II)
Uncertainty on jet cross section at LHC significantly reduced
RCarlin 2006 Aspen Winter Conference
Measurement of FL
Can be performed with a set of lowered p energies at HERA-2 (~10pb-1)
bull σr~F2(xQ2)-f(y)FL(xQ2) y=Q2sxbull measure cross sections at high-y and change y at fixed xQ2
(change s)
FL~sxg(xQ2)
direct measurement of the gluon
M Klein
RCarlin 2006 Aspen Winter Conference
Result of a simulation (MKlein)
bull Can get ΔFL ~ 10-20bull The measurement of FL can
have an impact mostly in the low-x gluon low-Q
bull Important test of QCD consistency
bull HERA is the only place to mesure it
bull Trade off with luminosity lost at high energy
bull Luminosity goes as Ep2
bull Setup the machinebull Problem are the present
detectors well tuned to the measurement (low-x low-Q2)
RCarlin 2006 Aspen Winter Conference
Overall improvement from HERA-II statistics
RCarlin 2006 Aspen Winter Conference
Combining H1 and ZEUS present data
Using H1 and ZEUS data together in standard QCD fits The improvement is marginal errors are dominated by systematics the data sets are not incompatible but pull against each otherhellip
RCarlin 2006 Aspen Winter Conference
Example on how the combined ldquoHERArdquo data set after the fit is betterthan each individual pointBeware still preliminary all pitfalls have to be worked out
Different method (Glazov) Global (Hessian) fit of H1 and ZEUS cross section data The idea is that we are measuring the same thing and the systematics of one experiment can be solved by the other taking into account correlations Indeed systematics are quite different between ZEUS and H1
It is a duty of the HERA community to provide the best PDFs
RCarlin 2006 Aspen Winter Conference
Diffractive Higgs production at LHC
2-10 fb
bullClean signal very good mass resolution for the exclusive process
bullNeed knowledge of the diffractive PDFs and GPD
O(100) fb
fi(zXIPtQ2)
RCarlin 2006 Aspen Winter Conference
HERA is measuring DVCS and eleastic VM production (ρφJΨ Υ)
which are in principle sensitive to GPDsbullVM data sensitive to gluon distribution at x~(MV
2+Q2)W2
(neglecting skeweness of the two gluons)
RCarlin 2006 Aspen Winter Conference
Example exclusive JΨ production in DISbullSmallest theoretical error in DVCS and ΥbullRates are low need HERA-2
RCarlin 2006 Aspen Winter Conference
Diffraction at HERA
bull ~10 of DIS NC events are diffractive (rapidity gap)
bull Hard process should be described by QCD (2g exchange)
bull QCD factorization a hard process and a structure function F2
D(4)(xIPtβQ2)
bull Measure the diffractive PDFsbullBackground to the exclusive diffraction at LH
bull Understand the gap survival probability
X
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
Results of H1 and ZEUS are compatible
But there are clear differences particularly at low-x in the gluon The differences are mostly from the dat sets not from the fits and prameterizations
NB the gluon is not directly measured in HERA enters in the PDFs from F2lnQ2
use exclusive measurements senitive to the gluons (jets charmhellip)
Example of differences between PDFs
RCarlin 2006 Aspen Winter Conference
bullSpread of existing PDFs gives 10 uncertainty on Higgs cross sections at LHC
bullSame in the W production (8)bullNeed to do better than this
Djouadi amp Ferrag
RCarlin 2006 Aspen Winter Conference
Not only experimental data but also QCD calculations need progress (NNLOhellip) for the PDF fits
Large evolution from HERA to LHC to high-Q2 and low-x
bull Is NLO (NNLO) DGLAP good enough
bull Collinear factorization kt effects
bull BFKL ln(1x) resummationbull Saturation non linear
evolution
Precise data from HERA should help models to disentangle these effects
RCarlin 2006 Aspen Winter Conference
HERA-2 is expecting an integrated luminosity ~700pb-1 (H1 and ZEUS have ~130pb-1 on tape from HERA-1) Various improvements are possible
bull Use Jet data in the fits with higher statistics
bull Increased statistics on high Q2 data
bull Measure FL
Improvements are also possible with present data
bull Improved systematicsbull Combined data fits
How can we improve with HERA-2 the uncertainty in the PDFs
RCarlin 2006 Aspen Winter Conference
Improves the mid- to high-x gluon distributions up to high scalesAllowes to fit without the low energy heavy target data (target corrections systematics)
The use of high statitics HERA-2 data brings a significative improvement
gluon fractional errorInclusion of DIS Jet and High-Et dijet photoproduction data in the PDFs fits
Even better using full statistics AND optimised jet cross sectionsmeasurements designed to optimise the sensitivity to the gluon density
C Gwenlan A Cooper-Sarkar CTargett-Adams
RCarlin 2006 Aspen Winter Conference
At high-Q2 high-x the NCCC measurement is still limited by statistics
Expect impact in the valence quarks distributions
The measurements at low-Q2 are already limited by the systematic uncertainties O(2-3)
bullH1 is planning to reduce the systematics at low-Q2 using HERA-I yr 2000 databullGoal is to reach 1 level will effect mostly low-x gluon
RCarlin 2006 Aspen Winter Conference
Simulation 500 pb-1 in the e+ and e- channels
Improvement up to a factor 2 in the valence
NB this is a ZEUS fit with jets cross sections and no low energy data results still improves wrt global fits
There are also improvements in xF3~Σ(q-qbar) up to a factor of three
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (I)
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (II)
Uncertainty on jet cross section at LHC significantly reduced
RCarlin 2006 Aspen Winter Conference
Measurement of FL
Can be performed with a set of lowered p energies at HERA-2 (~10pb-1)
bull σr~F2(xQ2)-f(y)FL(xQ2) y=Q2sxbull measure cross sections at high-y and change y at fixed xQ2
(change s)
FL~sxg(xQ2)
direct measurement of the gluon
M Klein
RCarlin 2006 Aspen Winter Conference
Result of a simulation (MKlein)
bull Can get ΔFL ~ 10-20bull The measurement of FL can
have an impact mostly in the low-x gluon low-Q
bull Important test of QCD consistency
bull HERA is the only place to mesure it
bull Trade off with luminosity lost at high energy
bull Luminosity goes as Ep2
bull Setup the machinebull Problem are the present
detectors well tuned to the measurement (low-x low-Q2)
RCarlin 2006 Aspen Winter Conference
Overall improvement from HERA-II statistics
RCarlin 2006 Aspen Winter Conference
Combining H1 and ZEUS present data
Using H1 and ZEUS data together in standard QCD fits The improvement is marginal errors are dominated by systematics the data sets are not incompatible but pull against each otherhellip
RCarlin 2006 Aspen Winter Conference
Example on how the combined ldquoHERArdquo data set after the fit is betterthan each individual pointBeware still preliminary all pitfalls have to be worked out
Different method (Glazov) Global (Hessian) fit of H1 and ZEUS cross section data The idea is that we are measuring the same thing and the systematics of one experiment can be solved by the other taking into account correlations Indeed systematics are quite different between ZEUS and H1
It is a duty of the HERA community to provide the best PDFs
RCarlin 2006 Aspen Winter Conference
Diffractive Higgs production at LHC
2-10 fb
bullClean signal very good mass resolution for the exclusive process
bullNeed knowledge of the diffractive PDFs and GPD
O(100) fb
fi(zXIPtQ2)
RCarlin 2006 Aspen Winter Conference
HERA is measuring DVCS and eleastic VM production (ρφJΨ Υ)
which are in principle sensitive to GPDsbullVM data sensitive to gluon distribution at x~(MV
2+Q2)W2
(neglecting skeweness of the two gluons)
RCarlin 2006 Aspen Winter Conference
Example exclusive JΨ production in DISbullSmallest theoretical error in DVCS and ΥbullRates are low need HERA-2
RCarlin 2006 Aspen Winter Conference
Diffraction at HERA
bull ~10 of DIS NC events are diffractive (rapidity gap)
bull Hard process should be described by QCD (2g exchange)
bull QCD factorization a hard process and a structure function F2
D(4)(xIPtβQ2)
bull Measure the diffractive PDFsbullBackground to the exclusive diffraction at LH
bull Understand the gap survival probability
X
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
bullSpread of existing PDFs gives 10 uncertainty on Higgs cross sections at LHC
bullSame in the W production (8)bullNeed to do better than this
Djouadi amp Ferrag
RCarlin 2006 Aspen Winter Conference
Not only experimental data but also QCD calculations need progress (NNLOhellip) for the PDF fits
Large evolution from HERA to LHC to high-Q2 and low-x
bull Is NLO (NNLO) DGLAP good enough
bull Collinear factorization kt effects
bull BFKL ln(1x) resummationbull Saturation non linear
evolution
Precise data from HERA should help models to disentangle these effects
RCarlin 2006 Aspen Winter Conference
HERA-2 is expecting an integrated luminosity ~700pb-1 (H1 and ZEUS have ~130pb-1 on tape from HERA-1) Various improvements are possible
bull Use Jet data in the fits with higher statistics
bull Increased statistics on high Q2 data
bull Measure FL
Improvements are also possible with present data
bull Improved systematicsbull Combined data fits
How can we improve with HERA-2 the uncertainty in the PDFs
RCarlin 2006 Aspen Winter Conference
Improves the mid- to high-x gluon distributions up to high scalesAllowes to fit without the low energy heavy target data (target corrections systematics)
The use of high statitics HERA-2 data brings a significative improvement
gluon fractional errorInclusion of DIS Jet and High-Et dijet photoproduction data in the PDFs fits
Even better using full statistics AND optimised jet cross sectionsmeasurements designed to optimise the sensitivity to the gluon density
C Gwenlan A Cooper-Sarkar CTargett-Adams
RCarlin 2006 Aspen Winter Conference
At high-Q2 high-x the NCCC measurement is still limited by statistics
Expect impact in the valence quarks distributions
The measurements at low-Q2 are already limited by the systematic uncertainties O(2-3)
bullH1 is planning to reduce the systematics at low-Q2 using HERA-I yr 2000 databullGoal is to reach 1 level will effect mostly low-x gluon
RCarlin 2006 Aspen Winter Conference
Simulation 500 pb-1 in the e+ and e- channels
Improvement up to a factor 2 in the valence
NB this is a ZEUS fit with jets cross sections and no low energy data results still improves wrt global fits
There are also improvements in xF3~Σ(q-qbar) up to a factor of three
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (I)
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (II)
Uncertainty on jet cross section at LHC significantly reduced
RCarlin 2006 Aspen Winter Conference
Measurement of FL
Can be performed with a set of lowered p energies at HERA-2 (~10pb-1)
bull σr~F2(xQ2)-f(y)FL(xQ2) y=Q2sxbull measure cross sections at high-y and change y at fixed xQ2
(change s)
FL~sxg(xQ2)
direct measurement of the gluon
M Klein
RCarlin 2006 Aspen Winter Conference
Result of a simulation (MKlein)
bull Can get ΔFL ~ 10-20bull The measurement of FL can
have an impact mostly in the low-x gluon low-Q
bull Important test of QCD consistency
bull HERA is the only place to mesure it
bull Trade off with luminosity lost at high energy
bull Luminosity goes as Ep2
bull Setup the machinebull Problem are the present
detectors well tuned to the measurement (low-x low-Q2)
RCarlin 2006 Aspen Winter Conference
Overall improvement from HERA-II statistics
RCarlin 2006 Aspen Winter Conference
Combining H1 and ZEUS present data
Using H1 and ZEUS data together in standard QCD fits The improvement is marginal errors are dominated by systematics the data sets are not incompatible but pull against each otherhellip
RCarlin 2006 Aspen Winter Conference
Example on how the combined ldquoHERArdquo data set after the fit is betterthan each individual pointBeware still preliminary all pitfalls have to be worked out
Different method (Glazov) Global (Hessian) fit of H1 and ZEUS cross section data The idea is that we are measuring the same thing and the systematics of one experiment can be solved by the other taking into account correlations Indeed systematics are quite different between ZEUS and H1
It is a duty of the HERA community to provide the best PDFs
RCarlin 2006 Aspen Winter Conference
Diffractive Higgs production at LHC
2-10 fb
bullClean signal very good mass resolution for the exclusive process
bullNeed knowledge of the diffractive PDFs and GPD
O(100) fb
fi(zXIPtQ2)
RCarlin 2006 Aspen Winter Conference
HERA is measuring DVCS and eleastic VM production (ρφJΨ Υ)
which are in principle sensitive to GPDsbullVM data sensitive to gluon distribution at x~(MV
2+Q2)W2
(neglecting skeweness of the two gluons)
RCarlin 2006 Aspen Winter Conference
Example exclusive JΨ production in DISbullSmallest theoretical error in DVCS and ΥbullRates are low need HERA-2
RCarlin 2006 Aspen Winter Conference
Diffraction at HERA
bull ~10 of DIS NC events are diffractive (rapidity gap)
bull Hard process should be described by QCD (2g exchange)
bull QCD factorization a hard process and a structure function F2
D(4)(xIPtβQ2)
bull Measure the diffractive PDFsbullBackground to the exclusive diffraction at LH
bull Understand the gap survival probability
X
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
Not only experimental data but also QCD calculations need progress (NNLOhellip) for the PDF fits
Large evolution from HERA to LHC to high-Q2 and low-x
bull Is NLO (NNLO) DGLAP good enough
bull Collinear factorization kt effects
bull BFKL ln(1x) resummationbull Saturation non linear
evolution
Precise data from HERA should help models to disentangle these effects
RCarlin 2006 Aspen Winter Conference
HERA-2 is expecting an integrated luminosity ~700pb-1 (H1 and ZEUS have ~130pb-1 on tape from HERA-1) Various improvements are possible
bull Use Jet data in the fits with higher statistics
bull Increased statistics on high Q2 data
bull Measure FL
Improvements are also possible with present data
bull Improved systematicsbull Combined data fits
How can we improve with HERA-2 the uncertainty in the PDFs
RCarlin 2006 Aspen Winter Conference
Improves the mid- to high-x gluon distributions up to high scalesAllowes to fit without the low energy heavy target data (target corrections systematics)
The use of high statitics HERA-2 data brings a significative improvement
gluon fractional errorInclusion of DIS Jet and High-Et dijet photoproduction data in the PDFs fits
Even better using full statistics AND optimised jet cross sectionsmeasurements designed to optimise the sensitivity to the gluon density
C Gwenlan A Cooper-Sarkar CTargett-Adams
RCarlin 2006 Aspen Winter Conference
At high-Q2 high-x the NCCC measurement is still limited by statistics
Expect impact in the valence quarks distributions
The measurements at low-Q2 are already limited by the systematic uncertainties O(2-3)
bullH1 is planning to reduce the systematics at low-Q2 using HERA-I yr 2000 databullGoal is to reach 1 level will effect mostly low-x gluon
RCarlin 2006 Aspen Winter Conference
Simulation 500 pb-1 in the e+ and e- channels
Improvement up to a factor 2 in the valence
NB this is a ZEUS fit with jets cross sections and no low energy data results still improves wrt global fits
There are also improvements in xF3~Σ(q-qbar) up to a factor of three
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (I)
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (II)
Uncertainty on jet cross section at LHC significantly reduced
RCarlin 2006 Aspen Winter Conference
Measurement of FL
Can be performed with a set of lowered p energies at HERA-2 (~10pb-1)
bull σr~F2(xQ2)-f(y)FL(xQ2) y=Q2sxbull measure cross sections at high-y and change y at fixed xQ2
(change s)
FL~sxg(xQ2)
direct measurement of the gluon
M Klein
RCarlin 2006 Aspen Winter Conference
Result of a simulation (MKlein)
bull Can get ΔFL ~ 10-20bull The measurement of FL can
have an impact mostly in the low-x gluon low-Q
bull Important test of QCD consistency
bull HERA is the only place to mesure it
bull Trade off with luminosity lost at high energy
bull Luminosity goes as Ep2
bull Setup the machinebull Problem are the present
detectors well tuned to the measurement (low-x low-Q2)
RCarlin 2006 Aspen Winter Conference
Overall improvement from HERA-II statistics
RCarlin 2006 Aspen Winter Conference
Combining H1 and ZEUS present data
Using H1 and ZEUS data together in standard QCD fits The improvement is marginal errors are dominated by systematics the data sets are not incompatible but pull against each otherhellip
RCarlin 2006 Aspen Winter Conference
Example on how the combined ldquoHERArdquo data set after the fit is betterthan each individual pointBeware still preliminary all pitfalls have to be worked out
Different method (Glazov) Global (Hessian) fit of H1 and ZEUS cross section data The idea is that we are measuring the same thing and the systematics of one experiment can be solved by the other taking into account correlations Indeed systematics are quite different between ZEUS and H1
It is a duty of the HERA community to provide the best PDFs
RCarlin 2006 Aspen Winter Conference
Diffractive Higgs production at LHC
2-10 fb
bullClean signal very good mass resolution for the exclusive process
bullNeed knowledge of the diffractive PDFs and GPD
O(100) fb
fi(zXIPtQ2)
RCarlin 2006 Aspen Winter Conference
HERA is measuring DVCS and eleastic VM production (ρφJΨ Υ)
which are in principle sensitive to GPDsbullVM data sensitive to gluon distribution at x~(MV
2+Q2)W2
(neglecting skeweness of the two gluons)
RCarlin 2006 Aspen Winter Conference
Example exclusive JΨ production in DISbullSmallest theoretical error in DVCS and ΥbullRates are low need HERA-2
RCarlin 2006 Aspen Winter Conference
Diffraction at HERA
bull ~10 of DIS NC events are diffractive (rapidity gap)
bull Hard process should be described by QCD (2g exchange)
bull QCD factorization a hard process and a structure function F2
D(4)(xIPtβQ2)
bull Measure the diffractive PDFsbullBackground to the exclusive diffraction at LH
bull Understand the gap survival probability
X
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
HERA-2 is expecting an integrated luminosity ~700pb-1 (H1 and ZEUS have ~130pb-1 on tape from HERA-1) Various improvements are possible
bull Use Jet data in the fits with higher statistics
bull Increased statistics on high Q2 data
bull Measure FL
Improvements are also possible with present data
bull Improved systematicsbull Combined data fits
How can we improve with HERA-2 the uncertainty in the PDFs
RCarlin 2006 Aspen Winter Conference
Improves the mid- to high-x gluon distributions up to high scalesAllowes to fit without the low energy heavy target data (target corrections systematics)
The use of high statitics HERA-2 data brings a significative improvement
gluon fractional errorInclusion of DIS Jet and High-Et dijet photoproduction data in the PDFs fits
Even better using full statistics AND optimised jet cross sectionsmeasurements designed to optimise the sensitivity to the gluon density
C Gwenlan A Cooper-Sarkar CTargett-Adams
RCarlin 2006 Aspen Winter Conference
At high-Q2 high-x the NCCC measurement is still limited by statistics
Expect impact in the valence quarks distributions
The measurements at low-Q2 are already limited by the systematic uncertainties O(2-3)
bullH1 is planning to reduce the systematics at low-Q2 using HERA-I yr 2000 databullGoal is to reach 1 level will effect mostly low-x gluon
RCarlin 2006 Aspen Winter Conference
Simulation 500 pb-1 in the e+ and e- channels
Improvement up to a factor 2 in the valence
NB this is a ZEUS fit with jets cross sections and no low energy data results still improves wrt global fits
There are also improvements in xF3~Σ(q-qbar) up to a factor of three
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (I)
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (II)
Uncertainty on jet cross section at LHC significantly reduced
RCarlin 2006 Aspen Winter Conference
Measurement of FL
Can be performed with a set of lowered p energies at HERA-2 (~10pb-1)
bull σr~F2(xQ2)-f(y)FL(xQ2) y=Q2sxbull measure cross sections at high-y and change y at fixed xQ2
(change s)
FL~sxg(xQ2)
direct measurement of the gluon
M Klein
RCarlin 2006 Aspen Winter Conference
Result of a simulation (MKlein)
bull Can get ΔFL ~ 10-20bull The measurement of FL can
have an impact mostly in the low-x gluon low-Q
bull Important test of QCD consistency
bull HERA is the only place to mesure it
bull Trade off with luminosity lost at high energy
bull Luminosity goes as Ep2
bull Setup the machinebull Problem are the present
detectors well tuned to the measurement (low-x low-Q2)
RCarlin 2006 Aspen Winter Conference
Overall improvement from HERA-II statistics
RCarlin 2006 Aspen Winter Conference
Combining H1 and ZEUS present data
Using H1 and ZEUS data together in standard QCD fits The improvement is marginal errors are dominated by systematics the data sets are not incompatible but pull against each otherhellip
RCarlin 2006 Aspen Winter Conference
Example on how the combined ldquoHERArdquo data set after the fit is betterthan each individual pointBeware still preliminary all pitfalls have to be worked out
Different method (Glazov) Global (Hessian) fit of H1 and ZEUS cross section data The idea is that we are measuring the same thing and the systematics of one experiment can be solved by the other taking into account correlations Indeed systematics are quite different between ZEUS and H1
It is a duty of the HERA community to provide the best PDFs
RCarlin 2006 Aspen Winter Conference
Diffractive Higgs production at LHC
2-10 fb
bullClean signal very good mass resolution for the exclusive process
bullNeed knowledge of the diffractive PDFs and GPD
O(100) fb
fi(zXIPtQ2)
RCarlin 2006 Aspen Winter Conference
HERA is measuring DVCS and eleastic VM production (ρφJΨ Υ)
which are in principle sensitive to GPDsbullVM data sensitive to gluon distribution at x~(MV
2+Q2)W2
(neglecting skeweness of the two gluons)
RCarlin 2006 Aspen Winter Conference
Example exclusive JΨ production in DISbullSmallest theoretical error in DVCS and ΥbullRates are low need HERA-2
RCarlin 2006 Aspen Winter Conference
Diffraction at HERA
bull ~10 of DIS NC events are diffractive (rapidity gap)
bull Hard process should be described by QCD (2g exchange)
bull QCD factorization a hard process and a structure function F2
D(4)(xIPtβQ2)
bull Measure the diffractive PDFsbullBackground to the exclusive diffraction at LH
bull Understand the gap survival probability
X
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
Improves the mid- to high-x gluon distributions up to high scalesAllowes to fit without the low energy heavy target data (target corrections systematics)
The use of high statitics HERA-2 data brings a significative improvement
gluon fractional errorInclusion of DIS Jet and High-Et dijet photoproduction data in the PDFs fits
Even better using full statistics AND optimised jet cross sectionsmeasurements designed to optimise the sensitivity to the gluon density
C Gwenlan A Cooper-Sarkar CTargett-Adams
RCarlin 2006 Aspen Winter Conference
At high-Q2 high-x the NCCC measurement is still limited by statistics
Expect impact in the valence quarks distributions
The measurements at low-Q2 are already limited by the systematic uncertainties O(2-3)
bullH1 is planning to reduce the systematics at low-Q2 using HERA-I yr 2000 databullGoal is to reach 1 level will effect mostly low-x gluon
RCarlin 2006 Aspen Winter Conference
Simulation 500 pb-1 in the e+ and e- channels
Improvement up to a factor 2 in the valence
NB this is a ZEUS fit with jets cross sections and no low energy data results still improves wrt global fits
There are also improvements in xF3~Σ(q-qbar) up to a factor of three
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (I)
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (II)
Uncertainty on jet cross section at LHC significantly reduced
RCarlin 2006 Aspen Winter Conference
Measurement of FL
Can be performed with a set of lowered p energies at HERA-2 (~10pb-1)
bull σr~F2(xQ2)-f(y)FL(xQ2) y=Q2sxbull measure cross sections at high-y and change y at fixed xQ2
(change s)
FL~sxg(xQ2)
direct measurement of the gluon
M Klein
RCarlin 2006 Aspen Winter Conference
Result of a simulation (MKlein)
bull Can get ΔFL ~ 10-20bull The measurement of FL can
have an impact mostly in the low-x gluon low-Q
bull Important test of QCD consistency
bull HERA is the only place to mesure it
bull Trade off with luminosity lost at high energy
bull Luminosity goes as Ep2
bull Setup the machinebull Problem are the present
detectors well tuned to the measurement (low-x low-Q2)
RCarlin 2006 Aspen Winter Conference
Overall improvement from HERA-II statistics
RCarlin 2006 Aspen Winter Conference
Combining H1 and ZEUS present data
Using H1 and ZEUS data together in standard QCD fits The improvement is marginal errors are dominated by systematics the data sets are not incompatible but pull against each otherhellip
RCarlin 2006 Aspen Winter Conference
Example on how the combined ldquoHERArdquo data set after the fit is betterthan each individual pointBeware still preliminary all pitfalls have to be worked out
Different method (Glazov) Global (Hessian) fit of H1 and ZEUS cross section data The idea is that we are measuring the same thing and the systematics of one experiment can be solved by the other taking into account correlations Indeed systematics are quite different between ZEUS and H1
It is a duty of the HERA community to provide the best PDFs
RCarlin 2006 Aspen Winter Conference
Diffractive Higgs production at LHC
2-10 fb
bullClean signal very good mass resolution for the exclusive process
bullNeed knowledge of the diffractive PDFs and GPD
O(100) fb
fi(zXIPtQ2)
RCarlin 2006 Aspen Winter Conference
HERA is measuring DVCS and eleastic VM production (ρφJΨ Υ)
which are in principle sensitive to GPDsbullVM data sensitive to gluon distribution at x~(MV
2+Q2)W2
(neglecting skeweness of the two gluons)
RCarlin 2006 Aspen Winter Conference
Example exclusive JΨ production in DISbullSmallest theoretical error in DVCS and ΥbullRates are low need HERA-2
RCarlin 2006 Aspen Winter Conference
Diffraction at HERA
bull ~10 of DIS NC events are diffractive (rapidity gap)
bull Hard process should be described by QCD (2g exchange)
bull QCD factorization a hard process and a structure function F2
D(4)(xIPtβQ2)
bull Measure the diffractive PDFsbullBackground to the exclusive diffraction at LH
bull Understand the gap survival probability
X
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
At high-Q2 high-x the NCCC measurement is still limited by statistics
Expect impact in the valence quarks distributions
The measurements at low-Q2 are already limited by the systematic uncertainties O(2-3)
bullH1 is planning to reduce the systematics at low-Q2 using HERA-I yr 2000 databullGoal is to reach 1 level will effect mostly low-x gluon
RCarlin 2006 Aspen Winter Conference
Simulation 500 pb-1 in the e+ and e- channels
Improvement up to a factor 2 in the valence
NB this is a ZEUS fit with jets cross sections and no low energy data results still improves wrt global fits
There are also improvements in xF3~Σ(q-qbar) up to a factor of three
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (I)
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (II)
Uncertainty on jet cross section at LHC significantly reduced
RCarlin 2006 Aspen Winter Conference
Measurement of FL
Can be performed with a set of lowered p energies at HERA-2 (~10pb-1)
bull σr~F2(xQ2)-f(y)FL(xQ2) y=Q2sxbull measure cross sections at high-y and change y at fixed xQ2
(change s)
FL~sxg(xQ2)
direct measurement of the gluon
M Klein
RCarlin 2006 Aspen Winter Conference
Result of a simulation (MKlein)
bull Can get ΔFL ~ 10-20bull The measurement of FL can
have an impact mostly in the low-x gluon low-Q
bull Important test of QCD consistency
bull HERA is the only place to mesure it
bull Trade off with luminosity lost at high energy
bull Luminosity goes as Ep2
bull Setup the machinebull Problem are the present
detectors well tuned to the measurement (low-x low-Q2)
RCarlin 2006 Aspen Winter Conference
Overall improvement from HERA-II statistics
RCarlin 2006 Aspen Winter Conference
Combining H1 and ZEUS present data
Using H1 and ZEUS data together in standard QCD fits The improvement is marginal errors are dominated by systematics the data sets are not incompatible but pull against each otherhellip
RCarlin 2006 Aspen Winter Conference
Example on how the combined ldquoHERArdquo data set after the fit is betterthan each individual pointBeware still preliminary all pitfalls have to be worked out
Different method (Glazov) Global (Hessian) fit of H1 and ZEUS cross section data The idea is that we are measuring the same thing and the systematics of one experiment can be solved by the other taking into account correlations Indeed systematics are quite different between ZEUS and H1
It is a duty of the HERA community to provide the best PDFs
RCarlin 2006 Aspen Winter Conference
Diffractive Higgs production at LHC
2-10 fb
bullClean signal very good mass resolution for the exclusive process
bullNeed knowledge of the diffractive PDFs and GPD
O(100) fb
fi(zXIPtQ2)
RCarlin 2006 Aspen Winter Conference
HERA is measuring DVCS and eleastic VM production (ρφJΨ Υ)
which are in principle sensitive to GPDsbullVM data sensitive to gluon distribution at x~(MV
2+Q2)W2
(neglecting skeweness of the two gluons)
RCarlin 2006 Aspen Winter Conference
Example exclusive JΨ production in DISbullSmallest theoretical error in DVCS and ΥbullRates are low need HERA-2
RCarlin 2006 Aspen Winter Conference
Diffraction at HERA
bull ~10 of DIS NC events are diffractive (rapidity gap)
bull Hard process should be described by QCD (2g exchange)
bull QCD factorization a hard process and a structure function F2
D(4)(xIPtβQ2)
bull Measure the diffractive PDFsbullBackground to the exclusive diffraction at LH
bull Understand the gap survival probability
X
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
Simulation 500 pb-1 in the e+ and e- channels
Improvement up to a factor 2 in the valence
NB this is a ZEUS fit with jets cross sections and no low energy data results still improves wrt global fits
There are also improvements in xF3~Σ(q-qbar) up to a factor of three
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (I)
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (II)
Uncertainty on jet cross section at LHC significantly reduced
RCarlin 2006 Aspen Winter Conference
Measurement of FL
Can be performed with a set of lowered p energies at HERA-2 (~10pb-1)
bull σr~F2(xQ2)-f(y)FL(xQ2) y=Q2sxbull measure cross sections at high-y and change y at fixed xQ2
(change s)
FL~sxg(xQ2)
direct measurement of the gluon
M Klein
RCarlin 2006 Aspen Winter Conference
Result of a simulation (MKlein)
bull Can get ΔFL ~ 10-20bull The measurement of FL can
have an impact mostly in the low-x gluon low-Q
bull Important test of QCD consistency
bull HERA is the only place to mesure it
bull Trade off with luminosity lost at high energy
bull Luminosity goes as Ep2
bull Setup the machinebull Problem are the present
detectors well tuned to the measurement (low-x low-Q2)
RCarlin 2006 Aspen Winter Conference
Overall improvement from HERA-II statistics
RCarlin 2006 Aspen Winter Conference
Combining H1 and ZEUS present data
Using H1 and ZEUS data together in standard QCD fits The improvement is marginal errors are dominated by systematics the data sets are not incompatible but pull against each otherhellip
RCarlin 2006 Aspen Winter Conference
Example on how the combined ldquoHERArdquo data set after the fit is betterthan each individual pointBeware still preliminary all pitfalls have to be worked out
Different method (Glazov) Global (Hessian) fit of H1 and ZEUS cross section data The idea is that we are measuring the same thing and the systematics of one experiment can be solved by the other taking into account correlations Indeed systematics are quite different between ZEUS and H1
It is a duty of the HERA community to provide the best PDFs
RCarlin 2006 Aspen Winter Conference
Diffractive Higgs production at LHC
2-10 fb
bullClean signal very good mass resolution for the exclusive process
bullNeed knowledge of the diffractive PDFs and GPD
O(100) fb
fi(zXIPtQ2)
RCarlin 2006 Aspen Winter Conference
HERA is measuring DVCS and eleastic VM production (ρφJΨ Υ)
which are in principle sensitive to GPDsbullVM data sensitive to gluon distribution at x~(MV
2+Q2)W2
(neglecting skeweness of the two gluons)
RCarlin 2006 Aspen Winter Conference
Example exclusive JΨ production in DISbullSmallest theoretical error in DVCS and ΥbullRates are low need HERA-2
RCarlin 2006 Aspen Winter Conference
Diffraction at HERA
bull ~10 of DIS NC events are diffractive (rapidity gap)
bull Hard process should be described by QCD (2g exchange)
bull QCD factorization a hard process and a structure function F2
D(4)(xIPtβQ2)
bull Measure the diffractive PDFsbullBackground to the exclusive diffraction at LH
bull Understand the gap survival probability
X
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (I)
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (II)
Uncertainty on jet cross section at LHC significantly reduced
RCarlin 2006 Aspen Winter Conference
Measurement of FL
Can be performed with a set of lowered p energies at HERA-2 (~10pb-1)
bull σr~F2(xQ2)-f(y)FL(xQ2) y=Q2sxbull measure cross sections at high-y and change y at fixed xQ2
(change s)
FL~sxg(xQ2)
direct measurement of the gluon
M Klein
RCarlin 2006 Aspen Winter Conference
Result of a simulation (MKlein)
bull Can get ΔFL ~ 10-20bull The measurement of FL can
have an impact mostly in the low-x gluon low-Q
bull Important test of QCD consistency
bull HERA is the only place to mesure it
bull Trade off with luminosity lost at high energy
bull Luminosity goes as Ep2
bull Setup the machinebull Problem are the present
detectors well tuned to the measurement (low-x low-Q2)
RCarlin 2006 Aspen Winter Conference
Overall improvement from HERA-II statistics
RCarlin 2006 Aspen Winter Conference
Combining H1 and ZEUS present data
Using H1 and ZEUS data together in standard QCD fits The improvement is marginal errors are dominated by systematics the data sets are not incompatible but pull against each otherhellip
RCarlin 2006 Aspen Winter Conference
Example on how the combined ldquoHERArdquo data set after the fit is betterthan each individual pointBeware still preliminary all pitfalls have to be worked out
Different method (Glazov) Global (Hessian) fit of H1 and ZEUS cross section data The idea is that we are measuring the same thing and the systematics of one experiment can be solved by the other taking into account correlations Indeed systematics are quite different between ZEUS and H1
It is a duty of the HERA community to provide the best PDFs
RCarlin 2006 Aspen Winter Conference
Diffractive Higgs production at LHC
2-10 fb
bullClean signal very good mass resolution for the exclusive process
bullNeed knowledge of the diffractive PDFs and GPD
O(100) fb
fi(zXIPtQ2)
RCarlin 2006 Aspen Winter Conference
HERA is measuring DVCS and eleastic VM production (ρφJΨ Υ)
which are in principle sensitive to GPDsbullVM data sensitive to gluon distribution at x~(MV
2+Q2)W2
(neglecting skeweness of the two gluons)
RCarlin 2006 Aspen Winter Conference
Example exclusive JΨ production in DISbullSmallest theoretical error in DVCS and ΥbullRates are low need HERA-2
RCarlin 2006 Aspen Winter Conference
Diffraction at HERA
bull ~10 of DIS NC events are diffractive (rapidity gap)
bull Hard process should be described by QCD (2g exchange)
bull QCD factorization a hard process and a structure function F2
D(4)(xIPtβQ2)
bull Measure the diffractive PDFsbullBackground to the exclusive diffraction at LH
bull Understand the gap survival probability
X
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
Impact on LHC from improved PDFs (II)
Uncertainty on jet cross section at LHC significantly reduced
RCarlin 2006 Aspen Winter Conference
Measurement of FL
Can be performed with a set of lowered p energies at HERA-2 (~10pb-1)
bull σr~F2(xQ2)-f(y)FL(xQ2) y=Q2sxbull measure cross sections at high-y and change y at fixed xQ2
(change s)
FL~sxg(xQ2)
direct measurement of the gluon
M Klein
RCarlin 2006 Aspen Winter Conference
Result of a simulation (MKlein)
bull Can get ΔFL ~ 10-20bull The measurement of FL can
have an impact mostly in the low-x gluon low-Q
bull Important test of QCD consistency
bull HERA is the only place to mesure it
bull Trade off with luminosity lost at high energy
bull Luminosity goes as Ep2
bull Setup the machinebull Problem are the present
detectors well tuned to the measurement (low-x low-Q2)
RCarlin 2006 Aspen Winter Conference
Overall improvement from HERA-II statistics
RCarlin 2006 Aspen Winter Conference
Combining H1 and ZEUS present data
Using H1 and ZEUS data together in standard QCD fits The improvement is marginal errors are dominated by systematics the data sets are not incompatible but pull against each otherhellip
RCarlin 2006 Aspen Winter Conference
Example on how the combined ldquoHERArdquo data set after the fit is betterthan each individual pointBeware still preliminary all pitfalls have to be worked out
Different method (Glazov) Global (Hessian) fit of H1 and ZEUS cross section data The idea is that we are measuring the same thing and the systematics of one experiment can be solved by the other taking into account correlations Indeed systematics are quite different between ZEUS and H1
It is a duty of the HERA community to provide the best PDFs
RCarlin 2006 Aspen Winter Conference
Diffractive Higgs production at LHC
2-10 fb
bullClean signal very good mass resolution for the exclusive process
bullNeed knowledge of the diffractive PDFs and GPD
O(100) fb
fi(zXIPtQ2)
RCarlin 2006 Aspen Winter Conference
HERA is measuring DVCS and eleastic VM production (ρφJΨ Υ)
which are in principle sensitive to GPDsbullVM data sensitive to gluon distribution at x~(MV
2+Q2)W2
(neglecting skeweness of the two gluons)
RCarlin 2006 Aspen Winter Conference
Example exclusive JΨ production in DISbullSmallest theoretical error in DVCS and ΥbullRates are low need HERA-2
RCarlin 2006 Aspen Winter Conference
Diffraction at HERA
bull ~10 of DIS NC events are diffractive (rapidity gap)
bull Hard process should be described by QCD (2g exchange)
bull QCD factorization a hard process and a structure function F2
D(4)(xIPtβQ2)
bull Measure the diffractive PDFsbullBackground to the exclusive diffraction at LH
bull Understand the gap survival probability
X
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
Measurement of FL
Can be performed with a set of lowered p energies at HERA-2 (~10pb-1)
bull σr~F2(xQ2)-f(y)FL(xQ2) y=Q2sxbull measure cross sections at high-y and change y at fixed xQ2
(change s)
FL~sxg(xQ2)
direct measurement of the gluon
M Klein
RCarlin 2006 Aspen Winter Conference
Result of a simulation (MKlein)
bull Can get ΔFL ~ 10-20bull The measurement of FL can
have an impact mostly in the low-x gluon low-Q
bull Important test of QCD consistency
bull HERA is the only place to mesure it
bull Trade off with luminosity lost at high energy
bull Luminosity goes as Ep2
bull Setup the machinebull Problem are the present
detectors well tuned to the measurement (low-x low-Q2)
RCarlin 2006 Aspen Winter Conference
Overall improvement from HERA-II statistics
RCarlin 2006 Aspen Winter Conference
Combining H1 and ZEUS present data
Using H1 and ZEUS data together in standard QCD fits The improvement is marginal errors are dominated by systematics the data sets are not incompatible but pull against each otherhellip
RCarlin 2006 Aspen Winter Conference
Example on how the combined ldquoHERArdquo data set after the fit is betterthan each individual pointBeware still preliminary all pitfalls have to be worked out
Different method (Glazov) Global (Hessian) fit of H1 and ZEUS cross section data The idea is that we are measuring the same thing and the systematics of one experiment can be solved by the other taking into account correlations Indeed systematics are quite different between ZEUS and H1
It is a duty of the HERA community to provide the best PDFs
RCarlin 2006 Aspen Winter Conference
Diffractive Higgs production at LHC
2-10 fb
bullClean signal very good mass resolution for the exclusive process
bullNeed knowledge of the diffractive PDFs and GPD
O(100) fb
fi(zXIPtQ2)
RCarlin 2006 Aspen Winter Conference
HERA is measuring DVCS and eleastic VM production (ρφJΨ Υ)
which are in principle sensitive to GPDsbullVM data sensitive to gluon distribution at x~(MV
2+Q2)W2
(neglecting skeweness of the two gluons)
RCarlin 2006 Aspen Winter Conference
Example exclusive JΨ production in DISbullSmallest theoretical error in DVCS and ΥbullRates are low need HERA-2
RCarlin 2006 Aspen Winter Conference
Diffraction at HERA
bull ~10 of DIS NC events are diffractive (rapidity gap)
bull Hard process should be described by QCD (2g exchange)
bull QCD factorization a hard process and a structure function F2
D(4)(xIPtβQ2)
bull Measure the diffractive PDFsbullBackground to the exclusive diffraction at LH
bull Understand the gap survival probability
X
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
Result of a simulation (MKlein)
bull Can get ΔFL ~ 10-20bull The measurement of FL can
have an impact mostly in the low-x gluon low-Q
bull Important test of QCD consistency
bull HERA is the only place to mesure it
bull Trade off with luminosity lost at high energy
bull Luminosity goes as Ep2
bull Setup the machinebull Problem are the present
detectors well tuned to the measurement (low-x low-Q2)
RCarlin 2006 Aspen Winter Conference
Overall improvement from HERA-II statistics
RCarlin 2006 Aspen Winter Conference
Combining H1 and ZEUS present data
Using H1 and ZEUS data together in standard QCD fits The improvement is marginal errors are dominated by systematics the data sets are not incompatible but pull against each otherhellip
RCarlin 2006 Aspen Winter Conference
Example on how the combined ldquoHERArdquo data set after the fit is betterthan each individual pointBeware still preliminary all pitfalls have to be worked out
Different method (Glazov) Global (Hessian) fit of H1 and ZEUS cross section data The idea is that we are measuring the same thing and the systematics of one experiment can be solved by the other taking into account correlations Indeed systematics are quite different between ZEUS and H1
It is a duty of the HERA community to provide the best PDFs
RCarlin 2006 Aspen Winter Conference
Diffractive Higgs production at LHC
2-10 fb
bullClean signal very good mass resolution for the exclusive process
bullNeed knowledge of the diffractive PDFs and GPD
O(100) fb
fi(zXIPtQ2)
RCarlin 2006 Aspen Winter Conference
HERA is measuring DVCS and eleastic VM production (ρφJΨ Υ)
which are in principle sensitive to GPDsbullVM data sensitive to gluon distribution at x~(MV
2+Q2)W2
(neglecting skeweness of the two gluons)
RCarlin 2006 Aspen Winter Conference
Example exclusive JΨ production in DISbullSmallest theoretical error in DVCS and ΥbullRates are low need HERA-2
RCarlin 2006 Aspen Winter Conference
Diffraction at HERA
bull ~10 of DIS NC events are diffractive (rapidity gap)
bull Hard process should be described by QCD (2g exchange)
bull QCD factorization a hard process and a structure function F2
D(4)(xIPtβQ2)
bull Measure the diffractive PDFsbullBackground to the exclusive diffraction at LH
bull Understand the gap survival probability
X
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
Overall improvement from HERA-II statistics
RCarlin 2006 Aspen Winter Conference
Combining H1 and ZEUS present data
Using H1 and ZEUS data together in standard QCD fits The improvement is marginal errors are dominated by systematics the data sets are not incompatible but pull against each otherhellip
RCarlin 2006 Aspen Winter Conference
Example on how the combined ldquoHERArdquo data set after the fit is betterthan each individual pointBeware still preliminary all pitfalls have to be worked out
Different method (Glazov) Global (Hessian) fit of H1 and ZEUS cross section data The idea is that we are measuring the same thing and the systematics of one experiment can be solved by the other taking into account correlations Indeed systematics are quite different between ZEUS and H1
It is a duty of the HERA community to provide the best PDFs
RCarlin 2006 Aspen Winter Conference
Diffractive Higgs production at LHC
2-10 fb
bullClean signal very good mass resolution for the exclusive process
bullNeed knowledge of the diffractive PDFs and GPD
O(100) fb
fi(zXIPtQ2)
RCarlin 2006 Aspen Winter Conference
HERA is measuring DVCS and eleastic VM production (ρφJΨ Υ)
which are in principle sensitive to GPDsbullVM data sensitive to gluon distribution at x~(MV
2+Q2)W2
(neglecting skeweness of the two gluons)
RCarlin 2006 Aspen Winter Conference
Example exclusive JΨ production in DISbullSmallest theoretical error in DVCS and ΥbullRates are low need HERA-2
RCarlin 2006 Aspen Winter Conference
Diffraction at HERA
bull ~10 of DIS NC events are diffractive (rapidity gap)
bull Hard process should be described by QCD (2g exchange)
bull QCD factorization a hard process and a structure function F2
D(4)(xIPtβQ2)
bull Measure the diffractive PDFsbullBackground to the exclusive diffraction at LH
bull Understand the gap survival probability
X
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
Combining H1 and ZEUS present data
Using H1 and ZEUS data together in standard QCD fits The improvement is marginal errors are dominated by systematics the data sets are not incompatible but pull against each otherhellip
RCarlin 2006 Aspen Winter Conference
Example on how the combined ldquoHERArdquo data set after the fit is betterthan each individual pointBeware still preliminary all pitfalls have to be worked out
Different method (Glazov) Global (Hessian) fit of H1 and ZEUS cross section data The idea is that we are measuring the same thing and the systematics of one experiment can be solved by the other taking into account correlations Indeed systematics are quite different between ZEUS and H1
It is a duty of the HERA community to provide the best PDFs
RCarlin 2006 Aspen Winter Conference
Diffractive Higgs production at LHC
2-10 fb
bullClean signal very good mass resolution for the exclusive process
bullNeed knowledge of the diffractive PDFs and GPD
O(100) fb
fi(zXIPtQ2)
RCarlin 2006 Aspen Winter Conference
HERA is measuring DVCS and eleastic VM production (ρφJΨ Υ)
which are in principle sensitive to GPDsbullVM data sensitive to gluon distribution at x~(MV
2+Q2)W2
(neglecting skeweness of the two gluons)
RCarlin 2006 Aspen Winter Conference
Example exclusive JΨ production in DISbullSmallest theoretical error in DVCS and ΥbullRates are low need HERA-2
RCarlin 2006 Aspen Winter Conference
Diffraction at HERA
bull ~10 of DIS NC events are diffractive (rapidity gap)
bull Hard process should be described by QCD (2g exchange)
bull QCD factorization a hard process and a structure function F2
D(4)(xIPtβQ2)
bull Measure the diffractive PDFsbullBackground to the exclusive diffraction at LH
bull Understand the gap survival probability
X
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
Example on how the combined ldquoHERArdquo data set after the fit is betterthan each individual pointBeware still preliminary all pitfalls have to be worked out
Different method (Glazov) Global (Hessian) fit of H1 and ZEUS cross section data The idea is that we are measuring the same thing and the systematics of one experiment can be solved by the other taking into account correlations Indeed systematics are quite different between ZEUS and H1
It is a duty of the HERA community to provide the best PDFs
RCarlin 2006 Aspen Winter Conference
Diffractive Higgs production at LHC
2-10 fb
bullClean signal very good mass resolution for the exclusive process
bullNeed knowledge of the diffractive PDFs and GPD
O(100) fb
fi(zXIPtQ2)
RCarlin 2006 Aspen Winter Conference
HERA is measuring DVCS and eleastic VM production (ρφJΨ Υ)
which are in principle sensitive to GPDsbullVM data sensitive to gluon distribution at x~(MV
2+Q2)W2
(neglecting skeweness of the two gluons)
RCarlin 2006 Aspen Winter Conference
Example exclusive JΨ production in DISbullSmallest theoretical error in DVCS and ΥbullRates are low need HERA-2
RCarlin 2006 Aspen Winter Conference
Diffraction at HERA
bull ~10 of DIS NC events are diffractive (rapidity gap)
bull Hard process should be described by QCD (2g exchange)
bull QCD factorization a hard process and a structure function F2
D(4)(xIPtβQ2)
bull Measure the diffractive PDFsbullBackground to the exclusive diffraction at LH
bull Understand the gap survival probability
X
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
Diffractive Higgs production at LHC
2-10 fb
bullClean signal very good mass resolution for the exclusive process
bullNeed knowledge of the diffractive PDFs and GPD
O(100) fb
fi(zXIPtQ2)
RCarlin 2006 Aspen Winter Conference
HERA is measuring DVCS and eleastic VM production (ρφJΨ Υ)
which are in principle sensitive to GPDsbullVM data sensitive to gluon distribution at x~(MV
2+Q2)W2
(neglecting skeweness of the two gluons)
RCarlin 2006 Aspen Winter Conference
Example exclusive JΨ production in DISbullSmallest theoretical error in DVCS and ΥbullRates are low need HERA-2
RCarlin 2006 Aspen Winter Conference
Diffraction at HERA
bull ~10 of DIS NC events are diffractive (rapidity gap)
bull Hard process should be described by QCD (2g exchange)
bull QCD factorization a hard process and a structure function F2
D(4)(xIPtβQ2)
bull Measure the diffractive PDFsbullBackground to the exclusive diffraction at LH
bull Understand the gap survival probability
X
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
HERA is measuring DVCS and eleastic VM production (ρφJΨ Υ)
which are in principle sensitive to GPDsbullVM data sensitive to gluon distribution at x~(MV
2+Q2)W2
(neglecting skeweness of the two gluons)
RCarlin 2006 Aspen Winter Conference
Example exclusive JΨ production in DISbullSmallest theoretical error in DVCS and ΥbullRates are low need HERA-2
RCarlin 2006 Aspen Winter Conference
Diffraction at HERA
bull ~10 of DIS NC events are diffractive (rapidity gap)
bull Hard process should be described by QCD (2g exchange)
bull QCD factorization a hard process and a structure function F2
D(4)(xIPtβQ2)
bull Measure the diffractive PDFsbullBackground to the exclusive diffraction at LH
bull Understand the gap survival probability
X
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
Example exclusive JΨ production in DISbullSmallest theoretical error in DVCS and ΥbullRates are low need HERA-2
RCarlin 2006 Aspen Winter Conference
Diffraction at HERA
bull ~10 of DIS NC events are diffractive (rapidity gap)
bull Hard process should be described by QCD (2g exchange)
bull QCD factorization a hard process and a structure function F2
D(4)(xIPtβQ2)
bull Measure the diffractive PDFsbullBackground to the exclusive diffraction at LH
bull Understand the gap survival probability
X
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
Diffraction at HERA
bull ~10 of DIS NC events are diffractive (rapidity gap)
bull Hard process should be described by QCD (2g exchange)
bull QCD factorization a hard process and a structure function F2
D(4)(xIPtβQ2)
bull Measure the diffractive PDFsbullBackground to the exclusive diffraction at LH
bull Understand the gap survival probability
X
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
First compilation of HERA F2
D(3)
Different methodsbull tagged proton LPS FPS
(clean but low statistics)bull rapidity gap (H1)bull Mx method (Zeus) based on
the distribution of lnMX2
Result
bull Reasonable agreement between H1 and ZEUS
bull There are regions of significant discrepancies
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
NLO QCD fit
Gluon dominates over the singlet
Almost a factor 2 difference in the gluon between Zeus and H1
More work needed More data will come from FPS (H1) and exclusive processes
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
QCD fit to inclusive diffractive data can predict the exclusive diffractive dijets production in DIS Same for diffractive DIS charm production Some confidence in the process
Diffractive PDFs are they process independent functions (hard scattering factorization)
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
HERA diffractive PDFs fail to describe diffractive hadron-hadron collisions at the Tevatron To be understood and quantified to export results to LHC
Factorization is broken by the interctions of the spectator quarks (multiple interactions) Soft interactions between the spectator fill the gap (gap survival probability reduced)
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
At HERA we can have hadron-hadron interactions ldquoresolvedrdquo photon in photoproduction where the photon hadronizes before the hard scattering So we should see that the rapidity gap fills in these interactionsNB at HERA we can switch ON and OFF the hadron-hadron studying direct vs resolved
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
For jets in photoproduction the NLO fit overestimates the data by a factor 2 in both ldquoresolvedrdquo and ldquodirectrdquo photon regimes contrary to what expected from ldquogap survivalrdquo models (suppression in resolved only) More work is needed Use ratio beween diffractive and inclusive Jets
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Outgoing Parton
Outgoing Parton
Multiple Interactions
MI (additional partonic remnant-remnant interactions) will certainly be an issue at LHC
Has HERA anything to say about that
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
4 jets event in photoproduction at HERA
bull High order photoproduction process
bull At low xγ (ldquoresolvedrdquo) it can be interpreted as hadron-hadron collisions
bull The inclusive sample is well described by standard PS models + MI (with hard scattering contribution to the underlying event)
bull Not conclusive but suggestive
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
Multiple Interaction Diffraction saturation relationship AGK cutting rule in QCD
Diffraction
MI
Saturation
Bartels Kowalski Sabio-Vera
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
Try to find observables sensitive to non-DGLAP evolution
Measure forward jets in DIS at HERA
Study non-DGLAP QCD evolution at low-x
bull low xbj
bull xjetgtgtxbj
bull E2Tjet~Q2
bull kT ordering (DGLAP DISENT) bull x ordering (BFKL)bull angular ordering (CCFM)
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
Standard pQCD gives poor description at low-x for forward jets but hadronization and scale uncertainties are large
bullNeed more statistics and phenomenological progress to improve the understanding
x
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
Open Heavy Quark Production at HERAimpact on LHC
bull At very high-Q2 heavy quarks distributions are of size comprable to light sea quarksndash Impact on lumi
processes (Z production)
bull The b quarks PDFs enter in a number of interesting process at LHC (as signal or background)ndash Higgs productionndash Searches
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
bull5 difference in the pp z production if b PDFs are neglectedbullNeed to know F2
b to 20 accuracy to get Z production at 1 level
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
bull Presently the b production cross section at HERA is relatively well described by NLO QCD some discrepancy in selected regions
bull No more a factor 2-3 of overall excess bull Still limited statistics from HERA-I (b into μ channel)
open b productiondijet in photoproduction
open b productionjet in DIS
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
bull H1 has shown the first F2b
measurements using the lifetime still limited in statistics (57pb-1)
bull In HERA-II ZEUS has a new microvertex (MVD)
bull The increased statistics and the use of vertex detectors will improve significantly (order of magnitude) the heavy flavours measurements at HERA-II
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-
RCarlin 2006 Aspen Winter Conference
Conclusions
bull The HERA experiments have performed many measurements essential for LHC
bull Many more have to come with HERA-IIbull Many things I did not mention
ndash Lot of theoreticalphenomenological developments in QCD triggered by HERA
ndash MC tools developments ndash Design of very forward region (leading proton
tagging)bull HERA will stop in July 2007 still lot of data
to come we are getting ready for a prompt analisys
- HERA for LHC
- Slide 2
- Slide 3
- Topics for this talk
- Parton distributions HERA results
- Slide 6
- Example of differences between PDFs
- Slide 8
- Slide 9
- How can we improve with HERA-2 the uncertainty in the PDFs
- Slide 11
- Slide 12
- Slide 13
- Impact on LHC from improved PDFs (I)
- Impact on LHC from improved PDFs (II)
- Measurement of FL
- Slide 17
- Overall improvement from HERA-II statistics
- Combining H1 and ZEUS present data
- Slide 20
- Diffractive Higgs production at LHC
- Slide 22
- Slide 23
- Diffraction at HERA
- Slide 25
- NLO QCD fit
- Slide 27
- Slide 28
- Slide 29
- Slide 30
- Multiple Interactions
- Slide 32
- Slide 33
- Slide 34
- Slide 35
- Open Heavy Quark Production at HERA impact on LHC
- Slide 37
- Slide 38
- Slide 39
- Conclusions
-