model dependent and model independent considerations on two photon exchange model dependent and...

Model dependent and model independent considerations

on two photon exchange

Egle Tomasi-GustafssonIRFU SPhN-Saclay

and IN2P3- IPN Orsay France

Egle Tomasi-Gustafsson Gatchina July 10 2012


Plan

bull Introduction bull Generalities

bull Model independent considerationsbull Space-likebull Time-like

bull What do data saybull Which alternative for GEp problem

bull Conclusions

bull Model dependent considerations


Two-Photon exchange

bull 1g-2g interference is of the order of a=e24p=1137 (in

usual calculations of radiative corrections one photon is lsquohardrsquo and one is lsquosoftrsquo)

bull ldquoInvent a mechanismrdquo to enhance this contribution

bull In the 70rsquos it was shown [J Gunion and L Stodolsky V

Franco FM Lev VN Boitsov L Kondratyuk and VB

Kopeliovich R Blankenbecker and J Gunion] that at

large momentum transfer due to the sharp decrease of

the FFs if the momentum is shared between the two

photons the 2g- contribution can become very large

bull The 2g amplitude is expected to be mostly imaginary

bull In this case the 1g-2g interference is more important in

time-like region as the Born amplitude is complex


Qualitative estimation of 2g exchange

From quark counting rules Fd ~ t-5 and FN~t-2 At t = 4 GeV2

For d 3He 4He 2g effect should appear at ~1 GeV2for protons ~ 10 GeV2

q2 q2

For ed elastic scattering


Two-Photon exchange in ed-scatterng

bull Discrepancy between the results from

ndash Hall A [LC Alexa et al PRL 82 1374 (1999)]

ndash Hall C [D Abbott et al PRL 82 1379 (1999)]

bull Model-independent parametrization of the

2g- contribution

bull Applied to ed-elastic scattering data

M P Rekalo E T-G and D Prout Phys Rev C60 042202 (1999)


Crossing Symmetry

Scattering and annihilation channels

- Described by the same amplitude

- function of two kinematical variables

p2 rarr ndash p1

k2 rarr ndash k2

- which scan different kinematical regions


1g

1g-2g interference

2g1g

M P Rekalo E T-G and D Prout Phys Rev C (1999)


The 1g-2g interference destroys the linearity

of the Rosenbluth plot

What about data


1g-2g interference


CA DA


From the data

deviation from linearity

ltlt 1

Parametrization of 2g-contribution for e+p

E T-G G Gakh Phys Rev C 72 015209 (2005)

)(1

1)( 2)(2 QfQF a

2222

22

]1[ a

Dγ(a)

m[GeV]Q

GC)(Qf

e+4He scattering

Spin 0 particle F(q2) in Born approximation

2 g exchange F1(sq2)F2(sq2)=F(q2) +f(sq2)

F(q2)~a0 F1(sq2)~a


GI Gakh and E T-G NuclPhys A838 (2010) 50-60

Linear fit to e+4He elastic scattering




bull One-photon exchange - Two form factors (real in SL complex in TL) - Functions of one variable (t)

16 amplitudes in the general caseP- and T-invariance of EM interaction

helicity conservation

Interaction of 4 spin frac12 fermions

bullTwo-photon exchange

- Three (complex) amplitudes - Functions of two variables (st)


Space-like region

Is it still possible to extract the laquo real raquo FFs in presence of 2g exchange

Possible but difficult


Determination of EM form factors in presence of 2g exchange

-electron and positron beams

- longitudinally polarized - in identical kinematical

conditions

M P Rekalo E T-G EPJA (2004) Nucl Phys A (2003)

Model independent considerations foreplusmn N scattering



Determination of EM form factors in presence of 2g exchange- electron and positron beams

- longitudinally polarized - in identical kinematical conditions

Generalization of the polarization method (A Akhiezer and MP Rekalo)

M P Rekalo and E T-G Nucl Phys A740 (2004) 271 M P Rekalo and E T-G Nucl Phys A742 (2004) 322


If no positron beamhellip

Either three T-odd polarization observableshellip

bull Ay unpolarized leptons transversally polarized target or Py outgoing nucleon polarization with unpolarized leptons unpolarized target

bull Depolarization tensor (Dab) dependence of the

b-component of the final nucleon polarization on the a-component of the nucleon target with longitudinally polarized leptons








Very difficult experimentsThree T-odd polarization observableshellipExpected small of the order of a triple spin correlations buthellip Model independent way

This ratio contains the lsquoTRUE lsquoform factors



Either three T-odd polarization observableshellipor five T-even polarization observableshellip among dsdW Px(le) Pz(le) Dxx Dyy Dzz Dxz

Again very difficult experiments

Only Model independent ways (without positron beams)



Time-like region

Is it still possible to extract the laquo real raquo FFs in presence of 2 g exchange

much easier

Time-like observables | GE| 2 and | GM| 2

As in SL region- Dependence on q2 contained in FFs- Even dependence on cos2 q (1g exchange)- No dependence on sign of FFs- Enhancement of magnetic term

but TL form factors are complex

A Zichichi S M Berman N Cabibbo R Gatto Il Nuovo Cimento XXIV 170 (1962)B Bilenkii C Giunti V Wataghin Z Phys C 59 475 (1993)G Gakh ET-G Nucl Phys A761120 (2005)



Unpolarized cross section

bull Induces four new termsbull Odd function of qbull Does not contribute at q =90deg

Two Photon Exchange

MP Rekalo and E T-G EPJA 22 331 (2004)GI Gakh and E T-G NPA761 120 (2005)


bullProperties of the TPE amplitudes with respect to the transformation cos = - cos ie -

(equivalent to non-linearity in Rosenbluth fit)

bullBased on these properties one can remove or single out TPE contribution

Symmetry relations

E T-G G Gakh NPA (2007)


bullDifferential cross section at complementary angles

Symmetry relations (annihilation)

The DIFFERENCE enhances the 2 g contribution

The SUM cancels the 2 gcontribution


What do data say


Radiative Return (ISR)

s

m

x

sin

xx

x)xs(W

s

m

s

Ex)m)(ppee()xs(W

s

m

cosddm

)ppee(d

e

2

22

122

2

2

2

2

e+ +e- p + p +

B Aubert ( BABAR Collaboration) Phys Rev D73 012005 (2006)


1877divide1950

Angular distribution

Eve

nts

02

vs

cos

q

2400divide30002200divide24002100divide2200

2025divide21001950divide2025

2 -g exchange


Angular Asymmetry

Mpp=1877-19

A=001plusmn002

Mpp=24-3

E T-G EA Kuraev S Bakmaev S Pacetti Phys Lett B (2008)


Structure Function method

e+ +e- p + p +

DE=005


EA Kuraev V Meledin Nucl Phys B


Fitting the angular distributions

E T-G and M P Rekalo Phys Lett B 504 291 (2001)

Cross section at 900 Angular asymmetry

The form of the differential cross section

is equivalent to




1 g exchange

Linear Fit in cos2q

2 g exchange Quadratic Fit in x=cosq


q2=54 GeV2

2 g 0


Forward

Backward


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020

Fitting the angular distributionshellip


Which alternative for Gep

Polarization experiments - JlabAI Akhiezer and MP Rekalo 1967

GEp collaboration1) standard dipole function

for the nucleon magnetic FFs GMp and GMn

2) linear deviation from the dipole function for the electric proton FF Gep

3) QCD scaling not reached3) Zero crossing of Gep4) contradiction between

polarized and unpolarized measurements

AJR Puckett et al PRL (2010)

PRC85 (2012) 045203



WHY these points are aligned


Rosenbluth separation

=05=02

=08

Contribution of the electric term

hellipto be compared to the absolute value of the error on s and to the size and e dependence of RC

ET-G Phys Part Nucl Lett 4 281 (2007)


Reduced cross section and RCData from L Andivahis et al Phys Rev D50 5491 (1994)

Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2

Radiative Corrected data

Raw data without RC

Slope from P M

E T-G G Gakh Phys Rev C (2005)


Radiative Corrections (ep)

RC to the cross section- large (may reach 40)- e and Q2 dependent- calculated at first order

May change the slope of sR

(and even the sign )Q2=5 GeV2

Q2=375 GeV2

Q2=175 GeV2

Andivahis et al PRD50 5491 (1994)

2MG2

EGR

CF Perdrisat Progr Part Nucl Phys 59694 (2007)


Experimental correlation

sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2

RC(e)only published values

Correlation (ltRCbull gte )


Scattered electron energy

All orders of PT needed beyond Mo amp Tsai approximation

Initial state emission

final state emission

Quasi-elastic scattering

3

Y0

Not so smallShift to LOWER Q2

Polarization ratio (e-dependence)


bull DATA No evidence of e-dependence at 1 level

bull MODELS large correction (opposite sign) at small ε

bullTheory corrections to the Born approximation at Q2= 25 GeV2 Y Bystritskiy EA Kuraev and ET-G PhysRevC75 015207 (2007) P Blunden et al Phys Rev C72034612 (2005) (mainly GM) A Afanasev et al Phys Rev D72013008 (2005) (mainly GE) NKivel and MVanderhaeghen Phys Rev Lett103092004 (2009) (high Q2)

bull SF method e-independent corrections


SummaryOur Suggestion for search of 2g effectsbull Search for model independent statements (MP Rekalo G Gakh)

bull Exact calculation in frame of QED (p~m)bull Prove that QED box is upper limit of QCD box diagrambull Study analytical properties of the Compton amplitudebull Compare to experimental data

Our Conclusions for elastic ep scatteringbull Two photon contribution is negligible (real part) (EA Kuraev)bull Radiative corrections are huge take into account higher order effects (Structure Functions method) ) (Yu Bystricky)

Look for Multiple Photon Exchange in e-A scatteringbull Small angle e or p or pbar - Heavy ion scatteringEA Kuraev M Shatnev ET-G PRC80 (2009) 018201

2g effects are expected to be larger in TL region (complex nature)


The Pauli and Dirac Form Factors

Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279

The electromagnetic current in terms of the Pauli and Dirac FFs

Related to the Sachs FFs

Systematics


Differential cross section (SF)


bull The structure function of the lepton

Energy fractions of the leptons

Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)

1 of the order of one2 from the even part of the cross section

cos q

Radiative correction factor


s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d

Integrated in all phase space for gProton structureless


QED versus QCD

Imaginary part of the 2g amplitude

electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2


Interference of 1 2 exchange

bullExplicit calculation for structureless proton ndash The contribution is small for unpolarized

and polarized ep scatteringndash Does not contain the enhancement factor

L ndash The relevant contribution to K is ~ 1

bull em (elastic) scattering is upper limit for epEAKuraev V Bytev Yu Bystricky ET-G Phys Rev D74 013003 (1076)


Simulations

Approximationsbull Neglect contributions to GEGMbull Consider only real part

Main effect odd cos -qdistribution

2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g


N=a0+a2cos q sinq +a1 cos2q a2~2g

Model dependent and model independent considerations on two

Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference

The 1g-2g interference destroys the linearity of the Rosenblu

1g-2g interference (2)

Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15

Model independent considerations for eplusmn N scattering


If no positron beamhellip (2)



Slide 21



Symmetry relations


What do data say



Angular Asymmetry



Fitting the angular distributions (2)






Slide 38

Slide 39


Reduced cross section and RC





Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58


Plan

bull Introduction bull Generalities

bull Model independent considerationsbull Space-likebull Time-like

bull What do data saybull Which alternative for GEp problem

bull Conclusions

bull Model dependent considerations


Two-Photon exchange

















q2 q2








2g- contribution




Crossing Symmetry




p2 rarr ndash p1

k2 rarr ndash k2



1g

1g-2g interference

2g1g





What about data


1g-2g interference


CA DA


From the data


ltlt 1



)(1

1)( 2)(2 QfQF a

2222

22

]1[ a

Dγ(a)

m[GeV]Q

GC)(Qf

e+4He scattering



F(q2)~a0 F1(sq2)~a














Space-like region







conditions































Time-like region


much easier









Two Photon Exchange






Symmetry relations








What do data say



s

m

x

sin

xx

x)xs(W

s

m

s

Ex)m)(ppee()xs(W

s

m

cosddm

)ppee(d

e

2

22

122

2

2

2

2

e+ +e- p + p +



1877divide1950


Eve

nts

02

vs

cos

q



2 -g exchange


Angular Asymmetry

Mpp=1877-19

A=001plusmn002

Mpp=24-3




e+ +e- p + p +

DE=005








is equivalent to




1 g exchange

Linear Fit in cos2q



q2=54 GeV2

2 g 0


Forward

Backward


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58


Two-Photon exchange

















q2 q2








2g- contribution




Crossing Symmetry




p2 rarr ndash p1

k2 rarr ndash k2



1g

1g-2g interference

2g1g





What about data


1g-2g interference


CA DA


From the data


ltlt 1



)(1

1)( 2)(2 QfQF a

2222

22

]1[ a

Dγ(a)

m[GeV]Q

GC)(Qf

e+4He scattering



F(q2)~a0 F1(sq2)~a














Space-like region







conditions































Time-like region


much easier









Two Photon Exchange






Symmetry relations








What do data say



s

m

x

sin

xx

x)xs(W

s

m

s

Ex)m)(ppee()xs(W

s

m

cosddm

)ppee(d

e

2

22

122

2

2

2

2

e+ +e- p + p +



1877divide1950


Eve

nts

02

vs

cos

q



2 -g exchange


Angular Asymmetry

Mpp=1877-19

A=001plusmn002

Mpp=24-3




e+ +e- p + p +

DE=005








is equivalent to




1 g exchange

Linear Fit in cos2q



q2=54 GeV2

2 g 0


Forward

Backward


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58





q2 q2








2g- contribution




Crossing Symmetry




p2 rarr ndash p1

k2 rarr ndash k2



1g

1g-2g interference

2g1g





What about data


1g-2g interference


CA DA


From the data


ltlt 1



)(1

1)( 2)(2 QfQF a

2222

22

]1[ a

Dγ(a)

m[GeV]Q

GC)(Qf

e+4He scattering



F(q2)~a0 F1(sq2)~a














Space-like region







conditions































Time-like region


much easier









Two Photon Exchange






Symmetry relations








What do data say



s

m

x

sin

xx

x)xs(W

s

m

s

Ex)m)(ppee()xs(W

s

m

cosddm

)ppee(d

e

2

22

122

2

2

2

2

e+ +e- p + p +



1877divide1950


Eve

nts

02

vs

cos

q



2 -g exchange


Angular Asymmetry

Mpp=1877-19

A=001plusmn002

Mpp=24-3




e+ +e- p + p +

DE=005








is equivalent to




1 g exchange

Linear Fit in cos2q



q2=54 GeV2

2 g 0


Forward

Backward


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58







2g- contribution




Crossing Symmetry




p2 rarr ndash p1

k2 rarr ndash k2



1g

1g-2g interference

2g1g





What about data


1g-2g interference


CA DA


From the data


ltlt 1



)(1

1)( 2)(2 QfQF a

2222

22

]1[ a

Dγ(a)

m[GeV]Q

GC)(Qf

e+4He scattering



F(q2)~a0 F1(sq2)~a














Space-like region







conditions































Time-like region


much easier









Two Photon Exchange






Symmetry relations








What do data say



s

m

x

sin

xx

x)xs(W

s

m

s

Ex)m)(ppee()xs(W

s

m

cosddm

)ppee(d

e

2

22

122

2

2

2

2

e+ +e- p + p +



1877divide1950


Eve

nts

02

vs

cos

q



2 -g exchange


Angular Asymmetry

Mpp=1877-19

A=001plusmn002

Mpp=24-3




e+ +e- p + p +

DE=005








is equivalent to




1 g exchange

Linear Fit in cos2q



q2=54 GeV2

2 g 0


Forward

Backward


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58


Crossing Symmetry




p2 rarr ndash p1

k2 rarr ndash k2



1g

1g-2g interference

2g1g





What about data


1g-2g interference


CA DA


From the data


ltlt 1



)(1

1)( 2)(2 QfQF a

2222

22

]1[ a

Dγ(a)

m[GeV]Q

GC)(Qf

e+4He scattering



F(q2)~a0 F1(sq2)~a














Space-like region







conditions































Time-like region


much easier









Two Photon Exchange






Symmetry relations








What do data say



s

m

x

sin

xx

x)xs(W

s

m

s

Ex)m)(ppee()xs(W

s

m

cosddm

)ppee(d

e

2

22

122

2

2

2

2

e+ +e- p + p +



1877divide1950


Eve

nts

02

vs

cos

q



2 -g exchange


Angular Asymmetry

Mpp=1877-19

A=001plusmn002

Mpp=24-3




e+ +e- p + p +

DE=005








is equivalent to




1 g exchange

Linear Fit in cos2q



q2=54 GeV2

2 g 0


Forward

Backward


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58


1g

1g-2g interference

2g1g





What about data


1g-2g interference


CA DA


From the data


ltlt 1



)(1

1)( 2)(2 QfQF a

2222

22

]1[ a

Dγ(a)

m[GeV]Q

GC)(Qf

e+4He scattering



F(q2)~a0 F1(sq2)~a














Space-like region







conditions































Time-like region


much easier









Two Photon Exchange






Symmetry relations








What do data say



s

m

x

sin

xx

x)xs(W

s

m

s

Ex)m)(ppee()xs(W

s

m

cosddm

)ppee(d

e

2

22

122

2

2

2

2

e+ +e- p + p +



1877divide1950


Eve

nts

02

vs

cos

q



2 -g exchange


Angular Asymmetry

Mpp=1877-19

A=001plusmn002

Mpp=24-3




e+ +e- p + p +

DE=005








is equivalent to




1 g exchange

Linear Fit in cos2q



q2=54 GeV2

2 g 0


Forward

Backward


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58




What about data


1g-2g interference


CA DA


From the data


ltlt 1



)(1

1)( 2)(2 QfQF a

2222

22

]1[ a

Dγ(a)

m[GeV]Q

GC)(Qf

e+4He scattering



F(q2)~a0 F1(sq2)~a














Space-like region







conditions































Time-like region


much easier









Two Photon Exchange






Symmetry relations








What do data say



s

m

x

sin

xx

x)xs(W

s

m

s

Ex)m)(ppee()xs(W

s

m

cosddm

)ppee(d

e

2

22

122

2

2

2

2

e+ +e- p + p +



1877divide1950


Eve

nts

02

vs

cos

q



2 -g exchange


Angular Asymmetry

Mpp=1877-19

A=001plusmn002

Mpp=24-3




e+ +e- p + p +

DE=005








is equivalent to




1 g exchange

Linear Fit in cos2q



q2=54 GeV2

2 g 0


Forward

Backward


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58


1g-2g interference


CA DA


From the data


ltlt 1



)(1

1)( 2)(2 QfQF a

2222

22

]1[ a

Dγ(a)

m[GeV]Q

GC)(Qf

e+4He scattering



F(q2)~a0 F1(sq2)~a














Space-like region







conditions































Time-like region


much easier









Two Photon Exchange






Symmetry relations








What do data say



s

m

x

sin

xx

x)xs(W

s

m

s

Ex)m)(ppee()xs(W

s

m

cosddm

)ppee(d

e

2

22

122

2

2

2

2

e+ +e- p + p +



1877divide1950


Eve

nts

02

vs

cos

q



2 -g exchange


Angular Asymmetry

Mpp=1877-19

A=001plusmn002

Mpp=24-3




e+ +e- p + p +

DE=005








is equivalent to




1 g exchange

Linear Fit in cos2q



q2=54 GeV2

2 g 0


Forward

Backward


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58


From the data


ltlt 1



)(1

1)( 2)(2 QfQF a

2222

22

]1[ a

Dγ(a)

m[GeV]Q

GC)(Qf

e+4He scattering



F(q2)~a0 F1(sq2)~a














Space-like region







conditions































Time-like region


much easier









Two Photon Exchange






Symmetry relations








What do data say



s

m

x

sin

xx

x)xs(W

s

m

s

Ex)m)(ppee()xs(W

s

m

cosddm

)ppee(d

e

2

22

122

2

2

2

2

e+ +e- p + p +



1877divide1950


Eve

nts

02

vs

cos

q



2 -g exchange


Angular Asymmetry

Mpp=1877-19

A=001plusmn002

Mpp=24-3




e+ +e- p + p +

DE=005








is equivalent to




1 g exchange

Linear Fit in cos2q



q2=54 GeV2

2 g 0


Forward

Backward


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58

e+4He scattering



F(q2)~a0 F1(sq2)~a














Space-like region







conditions































Time-like region


much easier









Two Photon Exchange






Symmetry relations








What do data say



s

m

x

sin

xx

x)xs(W

s

m

s

Ex)m)(ppee()xs(W

s

m

cosddm

)ppee(d

e

2

22

122

2

2

2

2

e+ +e- p + p +



1877divide1950


Eve

nts

02

vs

cos

q



2 -g exchange


Angular Asymmetry

Mpp=1877-19

A=001plusmn002

Mpp=24-3




e+ +e- p + p +

DE=005








is equivalent to




1 g exchange

Linear Fit in cos2q



q2=54 GeV2

2 g 0


Forward

Backward


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58












Space-like region







conditions































Time-like region


much easier









Two Photon Exchange






Symmetry relations








What do data say



s

m

x

sin

xx

x)xs(W

s

m

s

Ex)m)(ppee()xs(W

s

m

cosddm

)ppee(d

e

2

22

122

2

2

2

2

e+ +e- p + p +



1877divide1950


Eve

nts

02

vs

cos

q



2 -g exchange


Angular Asymmetry

Mpp=1877-19

A=001plusmn002

Mpp=24-3




e+ +e- p + p +

DE=005








is equivalent to




1 g exchange

Linear Fit in cos2q



q2=54 GeV2

2 g 0


Forward

Backward


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58





conditions































Time-like region


much easier









Two Photon Exchange






Symmetry relations








What do data say



s

m

x

sin

xx

x)xs(W

s

m

s

Ex)m)(ppee()xs(W

s

m

cosddm

)ppee(d

e

2

22

122

2

2

2

2

e+ +e- p + p +



1877divide1950


Eve

nts

02

vs

cos

q



2 -g exchange


Angular Asymmetry

Mpp=1877-19

A=001plusmn002

Mpp=24-3




e+ +e- p + p +

DE=005








is equivalent to




1 g exchange

Linear Fit in cos2q



q2=54 GeV2

2 g 0


Forward

Backward


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58





























Time-like region


much easier









Two Photon Exchange






Symmetry relations








What do data say



s

m

x

sin

xx

x)xs(W

s

m

s

Ex)m)(ppee()xs(W

s

m

cosddm

)ppee(d

e

2

22

122

2

2

2

2

e+ +e- p + p +



1877divide1950


Eve

nts

02

vs

cos

q



2 -g exchange


Angular Asymmetry

Mpp=1877-19

A=001plusmn002

Mpp=24-3




e+ +e- p + p +

DE=005








is equivalent to




1 g exchange

Linear Fit in cos2q



q2=54 GeV2

2 g 0


Forward

Backward


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58









Two Photon Exchange






Symmetry relations








What do data say



s

m

x

sin

xx

x)xs(W

s

m

s

Ex)m)(ppee()xs(W

s

m

cosddm

)ppee(d

e

2

22

122

2

2

2

2

e+ +e- p + p +



1877divide1950


Eve

nts

02

vs

cos

q



2 -g exchange


Angular Asymmetry

Mpp=1877-19

A=001plusmn002

Mpp=24-3




e+ +e- p + p +

DE=005








is equivalent to




1 g exchange

Linear Fit in cos2q



q2=54 GeV2

2 g 0


Forward

Backward


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58





Symmetry relations








What do data say



s

m

x

sin

xx

x)xs(W

s

m

s

Ex)m)(ppee()xs(W

s

m

cosddm

)ppee(d

e

2

22

122

2

2

2

2

e+ +e- p + p +



1877divide1950


Eve

nts

02

vs

cos

q



2 -g exchange


Angular Asymmetry

Mpp=1877-19

A=001plusmn002

Mpp=24-3




e+ +e- p + p +

DE=005








is equivalent to




1 g exchange

Linear Fit in cos2q



q2=54 GeV2

2 g 0


Forward

Backward


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58







What do data say



s

m

x

sin

xx

x)xs(W

s

m

s

Ex)m)(ppee()xs(W

s

m

cosddm

)ppee(d

e

2

22

122

2

2

2

2

e+ +e- p + p +



1877divide1950


Eve

nts

02

vs

cos

q



2 -g exchange


Angular Asymmetry

Mpp=1877-19

A=001plusmn002

Mpp=24-3




e+ +e- p + p +

DE=005








is equivalent to




1 g exchange

Linear Fit in cos2q



q2=54 GeV2

2 g 0


Forward

Backward


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58



s

m

x

sin

xx

x)xs(W

s

m

s

Ex)m)(ppee()xs(W

s

m

cosddm

)ppee(d

e

2

22

122

2

2

2

2

e+ +e- p + p +



1877divide1950


Eve

nts

02

vs

cos

q



2 -g exchange


Angular Asymmetry

Mpp=1877-19

A=001plusmn002

Mpp=24-3




e+ +e- p + p +

DE=005








is equivalent to




1 g exchange

Linear Fit in cos2q



q2=54 GeV2

2 g 0


Forward

Backward


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58


1877divide1950


Eve

nts

02

vs

cos

q



2 -g exchange


Angular Asymmetry

Mpp=1877-19

A=001plusmn002

Mpp=24-3




e+ +e- p + p +

DE=005








is equivalent to




1 g exchange

Linear Fit in cos2q



q2=54 GeV2

2 g 0


Forward

Backward


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58


Angular Asymmetry

Mpp=1877-19

A=001plusmn002

Mpp=24-3




e+ +e- p + p +

DE=005








is equivalent to




1 g exchange

Linear Fit in cos2q



q2=54 GeV2

2 g 0


Forward

Backward


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58



e+ +e- p + p +

DE=005








is equivalent to




1 g exchange

Linear Fit in cos2q



q2=54 GeV2

2 g 0


Forward

Backward


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58






is equivalent to




1 g exchange

Linear Fit in cos2q



q2=54 GeV2

2 g 0


Forward

Backward


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58




1 g exchange

Linear Fit in cos2q



q2=54 GeV2

2 g 0


Forward

Backward


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58


q2=54 GeV2

2 g 0


Forward

Backward


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58


q2=54 GeV2

2 g 002



q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58


q2=54 GeV2

2 g 005



q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58


q2=54 GeV2

2 g 020











PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58










PRC85 (2012) 045203






=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58





=05=02

=08






Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58



Q2=175 GeV2

Q2=5 GeV2

Q2=325 GeV2

Q2=4 GeV2

Q2=25 GeV2

Q2=7 GeV2

Q2=6 GeV2


Raw data without RC

Slope from P M







Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58






Q2=375 GeV2

Q2=175 GeV2


2MG2

EGR




sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58



sel=smeas RC

Q2 gt 2 GeV2

Q2 lt 2 GeV2









3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58







3

Y0
















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58















Normalization

F1p(0)=1 F2p(0)= κp

GEp(0)=1 GMp(0)=μp=279



Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58

Systematics






Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58





Partition function

Odd term

K-factor

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58

Charge Asymmetry



K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58


K-factor (hard)


cos q



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58



s=10 GeV2

cos q

Ncorr=Nraw(1+ )d

d



QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58


QED versus QCD


electronproton


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58


QED versus QCD

Q2=005 GeV2

Q2=12 GeV2

Q2=2 GeV2








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58








Simulations



2003 MGF

0203 MGF

03 MGF

0503 MGF

q2=5482138 GeV2


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58


002

q2=54 GeV2

q2= 82 GeV2

q2=138 GeV2

005 0201g 2g




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58




Slide 2

Two-Photon exchange



Crossing Symmetry

1g-2g interference



Slide 10

e+4He scattering


Slide 13

Slide 14

Slide 15






Slide 21



Symmetry relations


What do data say



Angular Asymmetry









Slide 38

Slide 39







Summary


Systematics


Charge Asymmetry

K-factor (hard)


QED versus QCD

QED versus QCD (2)


Simulations

Slide 57

Slide 58

model dependent and model independent considerations on two photon exchange model dependent and...

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