atlas first run scenarios for b physics

ATLAS first run scenarios ATLAS first run scenarios for for

B physicsB physics

Paula Eerola, Lund UniversityPaula Eerola, Lund UniversityOn behalf of the ATLAS collaborationOn behalf of the ATLAS collaboration

Beauty 2006, Oxford, 25-29 September 2006Beauty 2006, Oxford, 25-29 September 2006

Paula Eerola, Lund UniversityPaula Eerola, Lund UniversityBeauty 2006, Oxford, 25-29 September Beauty 2006, Oxford, 25-29 September

20062006

22

This talk includes:This talk includes:

IntroductionIntroduction A summary of the LHC start-up scenarioA summary of the LHC start-up scenario B-production in the LHC commissioning run B-production in the LHC commissioning run

(450 GeV + 450 GeV) until the end of 2007.(450 GeV + 450 GeV) until the end of 2007. The first physics run at 14 TeVThe first physics run at 14 TeV

a)a) Role of B-physics and Heavy Quarkonia Role of B-physics and Heavy Quarkonia events in understanding the detector, trigger events in understanding the detector, trigger and online/offline software with 100 pband online/offline software with 100 pb -1-1..

b)b) Strategies for B-physics with 100 pbStrategies for B-physics with 100 pb -1-1 - 1 fb - 1 fb-1-1


20062006

33

IntroductionIntroduction ATLAS is a general-purpose ATLAS is a general-purpose

experiment, with an experiment, with an emphasis on high-pemphasis on high-pTT physics physics beyond the Standard Model.beyond the Standard Model.

ATLAS has also capabilities ATLAS has also capabilities for a rich B-physics for a rich B-physics programme, thanks to programme, thanks to precise vertexing and precise vertexing and tracking, high-resolution tracking, high-resolution calorimetry, good muon calorimetry, good muon identification, and a identification, and a dedicated and flexible B-dedicated and flexible B-physics trigger scheme.physics trigger scheme.

ATLAS has a well-defined B-ATLAS has a well-defined B-physics programme for all physics programme for all stages of the LHC operation, stages of the LHC operation, from the commissioning run from the commissioning run all the way up to the highest all the way up to the highest luminosity running.luminosity running.


20062006

44

ATLAS B-physics goals: ATLAS B-physics goals: precision measurements and precision measurements and new physicsnew physics

mmss, , ss, , ss, , the weak phase the weak phase ss

Measurement Measurement of Bof Bs s

propertiesproperties

Precise measurements of the Precise measurements of the branching ratios and asymmetriesbranching ratios and asymmetriesRare decaysRare decays

Asymmetry parameter Asymmetry parameter bb, P, Pbb, , life-time measurementslife-time measurements

bb polarization polarization measurementsmeasurements

BBcc mass, mass, , QCD/EW interplay, QCD/EW interplay BBcc mesons mesons

sin(2sin(2) +) +NPNPCP violationCP violationeeJ

KJBsd

//

)(/ 0

)()(/

)()(/

,

JB

KKJB

ds

s

1,; aDBDB

sdsss

00

0*0

,

;

;

sb

dds

B

KBB

)()(/ pJb

/;/ JBJBcc

• CP-violation parametersCP-violation parameters• B-hadron parametersB-hadron parameters: masses, lifetimes, widths, oscillation : masses, lifetimes, widths, oscillation parameters, couplings, b-production, etc.parameters, couplings, b-production, etc.• Search for New Physics effectsSearch for New Physics effects: very rare decay modes, : very rare decay modes, forbidden decays/couplings, etc.forbidden decays/couplings, etc.


20062006

55

News from the LHC machine


20062006

66

P. Jenni ATLAS Overview Week July 2006

A new LHC schedule and turn-on strategy was presented to the A new LHC schedule and turn-on strategy was presented to the CERN SPC and Council June 2006. The main features of the new CERN SPC and Council June 2006. The main features of the new schedule are:schedule are:

The beam pipe closure date will be end of August 2007. The beam pipe closure date will be end of August 2007. LHC commissioning run with collisions LHC commissioning run with collisions at the injection energy (√s at the injection energy (√s =900 GeV), scheduled November 2007=900 GeV), scheduled November 2007. Luminosity typically L = . Luminosity typically L = 10102929cmcm-2-2ss-1-1.. During the commissioning run at 900 GeV the LHC will be a static During the commissioning run at 900 GeV the LHC will be a static machine, no ramp, no squeeze, to debug the machine and the machine, no ramp, no squeeze, to debug the machine and the detectors. detectors. Then there will be a shut-down (typically 3 months) during which Then there will be a shut-down (typically 3 months) during which the remaining machine sectors will be commissioned without beam the remaining machine sectors will be commissioned without beam to full energy (√s = 14 TeV).to full energy (√s = 14 TeV). After that the LHC will be brought into operation for After that the LHC will be brought into operation for the first the first physics run at 14 TeV, with the aim to integrate substantial physics run at 14 TeV, with the aim to integrate substantial luminosity by the end of 2008: goal several fbluminosity by the end of 2008: goal several fb-1-1 by the end of 2008. by the end of 2008.

New LHC machine schedule


20062006

77

The commissioning runThe commissioning run

b cross section dominates at both √s = 900 GeV and 14 TeV.

At √s = 900 GeV the b fraction of total inelastic events is ~10 x smaller than at 14 TeV.

• The run in 2007 will The run in 2007 will primarily be a detector and primarily be a detector and computing commissioning computing commissioning run, much more than a run, much more than a physics run. physics run. • A few weeks of stable A few weeks of stable running conditions at the running conditions at the injection energy.injection energy.

b

b


20062006

88

Triggers for the Triggers for the commissioning runningcommissioning running

√√s = 0.9 TeV, L = 10s = 0.9 TeV, L = 102929cmcm-2-2ss-1-1, , inelinel=40 mb <=> 4 =40 mb <=> 4 kHz interaction ratekHz interaction rate

Commissioning the detector, the trigger, the Commissioning the detector, the trigger, the offline reconstruction and analysis chainsoffline reconstruction and analysis chains

Data taking with loose level-1 (LVL1) single Data taking with loose level-1 (LVL1) single muon triggers (pmuon triggers (pTT>5 GeV) or minimum bias >5 GeV) or minimum bias triggerstriggers

The High Level Trigger (HLT) in pass-through The High Level Trigger (HLT) in pass-through mode for testingmode for testing

See J. Kirk’s talk on ATLAS triggersSee J. Kirk’s talk on ATLAS triggers


20062006

99

DecayDecay RateRate N(ev) forN(ev) for1 d* 1 d*

N(ev) for N(ev) for 30 d*30 d*

Min bias hadron Min bias hadron 55X |X ||<2.5|<2.5

1400 * 101400 * 10-4-4 Hz Hz 3 6003 600 109 000109 000

b b 55X X 60 * 1060 * 10-4 -4 Hz Hz 150150 4 700 4 700

b b 5533XX 2 * 102 * 10-4-4 Hz Hz 5.25.2 150150

b b J/J/5533 XX 0.1 * 100.1 * 10-4 -4 Hz Hz 0.30.3 88

pp pp J/ J/5533XX 1 * 101 * 10-4 -4 Hz Hz 33 8080

pp pp 5533 1.7 * 101.7 * 10-4 -4 HzHz 4.44.4 130130

*) 1 full day is 8.64 * 104 s, 30% machine and data taking efficiency assumed

√√ss =900 GeV, L=1029cm-2s-1

Rates and statistics

b

b

b


20062006

1010

Event statistics with B and Quarkonium muonic decays

bb 5 X

bb 53 X

pp J/ (53) X

pp (53) X

√√ss =900 GeV, L=1029cm-2s-1

h 5 X

bb J/ (53)X

Number of days of data taking

Nu

mb

er

of

even

ts in

ATLA

S a

fter

all

cu

ts

30% machine and data taking efficiency assumed. Reconstruction and trigger efficiencies included.


20062006

1111 30% data taking efficiency included.Efficiency of trigger and analysis cuts included.

Event statistics for the commissioning run

W e Z ee

bb 53Xpp + bb J/(53)X

√√ss =900 GeV, L=1029cm-2s-1


20062006

1212

Conclusions for Conclusions for the the commissioning commissioning runrun Heavy flavours b and c will be a source of ~4.7k single muons and Heavy flavours b and c will be a source of ~4.7k single muons and

~370 di-muons given 30 days of beam (30% machine and data ~370 di-muons given 30 days of beam (30% machine and data

taking efficiency).taking efficiency).

Soft LVL1 single-muon trigger can be used to select those events.Soft LVL1 single-muon trigger can be used to select those events.

High-level trigger in pass-through mode.High-level trigger in pass-through mode.

The dimuon sample includes about 90 J/The dimuon sample includes about 90 J/ and 130 and 130 – –

can serve for first tests of mass reconstruction.can serve for first tests of mass reconstruction.

Any heavy flavour physics? Low statistics will not allow Any heavy flavour physics? Low statistics will not allow

separating direct and indirect J/separating direct and indirect J/sources. S/B a factor of 10 sources. S/B a factor of 10

worse than at the nominal LHC c.m. energy. Muons from hadron worse than at the nominal LHC c.m. energy. Muons from hadron

decays dominate the trigger rate due to worse S/B and softer decays dominate the trigger rate due to worse S/B and softer

spectrum. The ratio of J/spectrum. The ratio of J/and and events may be the best bet. events may be the best bet.


20062006

1313

The first physics run: The first physics run: B-physics strategiesB-physics strategies- Serve as a tool for understanding the trigger and - Serve as a tool for understanding the trigger and

the detector: calibration, alignment, material, the detector: calibration, alignment, material,

magnetic field, event reconstruction.magnetic field, event reconstruction.

- Physics: cross-section measurements at new - Physics: cross-section measurements at new

energy - QCD tests and optimization of B-trigger energy - QCD tests and optimization of B-trigger

strategies.strategies.

- Control B-channels will be used to verify if we - Control B-channels will be used to verify if we

measure correctly well known B-physics quantities measure correctly well known B-physics quantities

(with increasing integrated luminosity (with increasing integrated luminosity real real

measurements).measurements).

- Control B-channels will also be used to prepare for - Control B-channels will also be used to prepare for

high-precision B-measurements and searches for high-precision B-measurements and searches for

rare decays: tagging calibration, production rare decays: tagging calibration, production

asymmetries, background channels specific for rare asymmetries, background channels specific for rare

decays.decays.


20062006

1414

Trigger priorities for Trigger priorities for the first physics the first physics runningrunning

√√s = 14 TeV, L = 10s = 14 TeV, L = 1032-3332-33cmcm-2-2ss-1-1

Many customers for the dataMany customers for the data– Data for commissioning the detector, the trigger, Data for commissioning the detector, the trigger,

the offline reconstruction and analysis chainsthe offline reconstruction and analysis chains– Data samples high-pData samples high-pTT physics studies physics studies– Data samples for B-physics studiesData samples for B-physics studies

Scope depends on luminosity and available Scope depends on luminosity and available HLT resourcesHLT resources

– Data samples for “minimum-bias” physics Data samples for “minimum-bias” physics studiesstudies Needed also for tuning Monte Carlo generators Needed also for tuning Monte Carlo generators

used in other physics studiesused in other physics studies


20062006

1515

Trigger menus for B-Trigger menus for B-physicsphysics

The ATLAS B-physics programme is based on LVL1 muon The ATLAS B-physics programme is based on LVL1 muon triggers triggers – Inclusive low-pInclusive low-pTT single-muon triggers at low luminosity single-muon triggers at low luminosity– Low-pLow-pTT dimuon triggers at higher luminosities dimuon triggers at higher luminosities

Search for specific final states (exclusive or semi-Search for specific final states (exclusive or semi-exclusive) in HLT exclusive) in HLT – Refine muon selection, then reconstruct Refine muon selection, then reconstruct

tracks from B decays in the inner tracks from B decays in the inner detector (ID)detector (ID)

Tracks in ID: track search in the full ID Tracks in ID: track search in the full ID or in regions given by LVL1 Regions of or in regions given by LVL1 Regions of Interests (RoIs), depending on the HLT Interests (RoIs), depending on the HLT processor capacity and luminosityprocessor capacity and luminosity

See J. KirkSee J. KirkEM RoI

e+ e-


20062006

1616

B cross-section at B cross-section at LHCLHC

• All LHC experiments plan to All LHC experiments plan to measure B-cross section in measure B-cross section in proton-proton collisions. proton-proton collisions.

• Measurements will cover Measurements will cover different phase space – will be different phase space – will be complementary.complementary.

• Partial phase-space overlaps: Partial phase-space overlaps: LHCb, ATLAS, CMS, ALICE - LHCb, ATLAS, CMS, ALICE - opportunity for cross-checks.opportunity for cross-checks.

• Methods of measurement for Methods of measurement for low- and medium-plow- and medium-pTT events in events in ATLASATLAS • b 6 X ;• b → 63 X; • Exclusive channels B+→J/

K+, B0→ J/ K0*

• b- correlations: B→J/ X +

b =J/ -

b

b

b


20062006

1717

Statistics for cross-section and correlation measurements

DecayDecay Statistics Statistics with 10 pbwith 10 pb-1-1

Statistics Statistics with 100 pbwith 100 pb-1-1

b b 66XX 40 M40 M 400 M400 M

c c 66XX 20 M20 M 200 M 200 M

b b XX 2 M2 M 20 M20 M

B B J/J/ X X and b and b X X

2 5002 500 25 00025 000

BB++→→J/J/KK++ 1 7001 700 17 00017 000

BB00→ → J/J/KK0*0* 870870 8 7008 700

b

b

c


20062006

1818

DecayDecay Statistics Statistics with 100 with 100 pbpb-1-1

MeasurementMeasurement

pp pp →→ J/ J/6633 1000 k1000 k R(b R(b → → J/J/)/R()/R(pp pp → → J/J/R(pp R(pp → → /R(/R(pp pp → → J/J/b b J/J/6633XX 400 k400 k

6633 100 k100 k

B-physics with 100 pbB-physics with 100 pb-1-1: : J/J/ and and

b

b


20062006

1919

B physics with 100 pbB physics with 100 pb-1-1: : exclusive B decaysexclusive B decaysDecayDecay Statistics withStatistics with

100 pb100 pb-1-1

MeasurementMeasurement

BB++→→J/J/KK++ 17 00017 000 Important reference Important reference and control channel: and control channel: new channels (Bnew channels (B→→) ) relative to this. relative to this.

BB00→ → J/J/KK0*0* 8 700 8 700 Control channels: Control channels: masses, lifetimes masses, lifetimes etc.etc.

Sensitive checks for Sensitive checks for understanding the understanding the Inner Detector.Inner Detector.

BB00→ → J/J/KKss 1 3001 300

BBss→ → J/J/ 900900

bb→→ J/ J/ 260260

BBss →→ D Dss 2525 Hadronic channels – Hadronic channels – only prepare only prepare methods for later methods for later measurements.measurements.


20062006

2020

The reconstructed masses and lifetimes of the The reconstructed masses and lifetimes of the well-known control channels are sensitive well-known control channels are sensitive tests of those detector features which have a tests of those detector features which have a strong impact on B-physics measurements.strong impact on B-physics measurements.

DecayDecay StatisticStatisticss

100 pb100 pb-1-1

Statistical Statistical error on error on lifetime lifetime

World av today World av today (stat + (stat + syst) syst)

BB++ BB++→→J/J/KK++ 17 00017 000 1.5 %1.5 % 0.4 %0.4 %

BB00 BB00→ → J/J/KK0*0* 8 7008 700 2.2 %2.2 % 0.5 %0.5 %

BBss BBss→ → J/J/ 900900 6 %6 % 2 %2 %

bb bb→→ J/J/ 260260 8 %8 % 5 %5 %

Lifetime “reconstruction” Lifetime “reconstruction” with control channelswith control channels


20062006

2121

B physics with 100 pbB physics with 100 pb-1-1: : sensitivity to sensitivity to rare rare exclusive B decaysexclusive B decays

DecayDecay Statistics Statistics or limit or limit withwith

100 pb100 pb-1-1

Measurement todayMeasurement today

BB++→→KK++ 2323 Belle today 80?Belle today 80? BB00→ → KK0*0* 1212

BBss→ → 99

bb→→ 33

BBss→→ 6.4×106.4×10-8-8 at at 90% C.L.90% C.L.

CDF currently 8.0x10 CDF currently 8.0x10 -8 -8

at 90% C.L.at 90% C.L.


20062006

2222

BB00ss→ µ→ µ++µµ-- with 100 pb with 100 pb-1-1, ,

10 fb10 fb-1-1 and 30 fb and 30 fb-1-1

IntegrateIntegrated LHC d LHC

luminositluminosityy

N(signaN(signal) after l) after all cutsall cuts

N(backgr.) N(backgr.) after all after all

cutscuts

ATLAS upper ATLAS upper limit for limit for

Br(Br(BB00ss→ µ→ µ++µµ-- ))

at 90% C.L.at 90% C.L.

CDF upper CDF upper limit for limit for Br(Br(BB00

ss→ → µµ++µµ-- ))

at 90% C.L.at 90% C.L.

100 pb100 pb-1-1 ~ 0~ 0 ~ 0.2~ 0.2 6 ×106 ×10-8-8

8.0×108.0×10-8-8 10 fb10 fb-1-1 ~ 7~ 7 ~ 20~ 20 1.2×101.2×10-8-8

30 fb30 fb-1-1 ~ 21~ 21 ~ 60~ 60 7 ×107 ×10-9-9

Discovery channel Discovery channel BB00ss→ µ→ µ++µµ--


20062006

2323

ConclusionConclusionssCommissioning run at 900 GeV, very low luminosityCommissioning run at 900 GeV, very low luminosity

Commissioning of the detector, the trigger, the offline Commissioning of the detector, the trigger, the offline reconstruction and the analysis chains.reconstruction and the analysis chains.

In 30 days ~4.7k single muons and ~370 di-muons from In 30 days ~4.7k single muons and ~370 di-muons from b and c: first tests of trigger and offline muon b and c: first tests of trigger and offline muon reconstruction.reconstruction.

90 J/90 J/ and 130 and 130 : first tests of mass reconstruction.: first tests of mass reconstruction.First physics run at 14 TeV, 100 pbFirst physics run at 14 TeV, 100 pb-1-1 – 1 fb – 1 fb-1-1

Measurements of B masses and lifetimes: a sensitive Measurements of B masses and lifetimes: a sensitive test of understanding the detector – alignment, test of understanding the detector – alignment, material, magnetic field, event reconstruction etc.material, magnetic field, event reconstruction etc.

Cross-section measurements at new energy: QCD tests Cross-section measurements at new energy: QCD tests and also optimization of B-trigger strategies.and also optimization of B-trigger strategies.

J/J/ and and measurements. measurements. Control B-channel measurements to prepare for further Control B-channel measurements to prepare for further

B physics – precision measurements and new physics B physics – precision measurements and new physics measurements.measurements.

With 100 pbWith 100 pb-1-1 ATLAS can achieve a sensitivity of ATLAS can achieve a sensitivity of 6.4×106.4×10-8-8 in the discovery channel in the discovery channel Br(Br(BB00

ss→ µ→ µ++µµ- - ), ), which which is at the level of current Tevatron results.is at the level of current Tevatron results.


20062006

2424

Thank you!Thank you!


20062006

2525

BACKUP SLIDESBACKUP SLIDES


20062006

2626

ProcessProcess Cross-Cross-section at √section at √s s

= 14 TeV= 14 TeV

Cross-section Cross-section at √at √s = 900 s = 900

GeVGeV Total LHC bb cross section Total LHC bb cross section 500500 bb 2525 bb

Total LHC inelastic Total LHC inelastic 7070 mbmb 4040 mbmb

Min bias hadron Min bias hadron 6(5)6(5)X |X |||<2.5<2.5

10 00010 000 nbnb 1 4001 400 nbnb

b b 6(5)6(5)X X 4 0004 000 nbnb 6060 nbnb

b b 6(5)6(5)33X*X* 200200 nbnb 22 nbnb

b b J/J/6(5)6(5)3)3)X*X* 77 nbnb 0.10.1 nbnb

pp pp J/ J/6(5)6(5)33X*X* 2828 nbnb 11 nbnb

pp pp 6(5)6(5)33 99 nbnb 1.71.7 nbnb

*) Dimuon pT cuts for muon reconstruction and identification are: (6, 3) GeV at 14 TeV and (5, 3) GeV for 900 GeV. For both muons ||<2.5.

Cross sections in ATLAS for muonic channels

b

b

b


20062006

2727

The figure shows sources of low-pT muons at 14 TeV.

Muons from hadron decays in flight (“h” in the figure) have a softer spectrum than muons from b.

At 900 GeV their relative contribution is larger – b fraction of total inelastic cross section ~ 10 smaller than at 14 TeV.

single-muon

di-muon

all

all

h

h

b

b

c

c

J/

Sources of low-pT single and double muons

LVL1 muon trigger rates @ 14 TeV and 1033cm-2s-1

b


20062006

2828

Cross sections for several dominant channels: in LHC (yellow) and in ATLAS volume (rest).

1414 TeVTeV 900900 GeVGeV

Total LHC inelastic (NSD) Total LHC inelastic (NSD) 7070 mbmb 4040 mbmb

Total LHC bb cross section Total LHC bb cross section 500500 bb 2525 bb

jet pjet pTT>15GeV |>15GeV |<2.5<2.5 2424 bb

Min bias Min bias X |X ||<2.5|<2.5 1000100000

nbnb 14001400 nbnb

b-jet pb-jet pTT>15GeV |>15GeV |<2.5<2.5 370370 nbnb

jet pjet pTT>50 GeV |>50 GeV |<2.5<2.5 4545 nbnb

bb bb X |X ||<2.5|<2.5 40004000 nbnb 6060 nbnb

bb bb X |X ||<2.5|<2.5 200200 nbnb 22 nbnb

pp pp ||||<2.5<2.5

99 nbnb 1.71.7 nbnb

pp pp J/J/X X ||||<2.5<2.5

2828 nbnb 11 nbnb

b-jet pb-jet pTT>50 GeV |>50 GeV |<2.5<2.5 0.630.63 nbnb

bb bb J/J/X X ||||<2.5<2.5

77 nbnb 0.10.1 nbnb*) muon pT cuts for 14TeV (900 GeV)


20062006

2929

ratesrates 30d = 1030d = 1066ss

jet pjet pTT>15GeV |>15GeV |<2.5<2.5 2424 1010-1-1 Hz Hz 2 400 0002 400 000

Min bias Min bias X |X ||<2.5|<2.5 14001400 1010-4-4 Hz Hz 140 000140 000

b-jet pb-jet pTT>15GeV |>15GeV |<2.5<2.5 370370 1010-4-4 Hz Hz 37 00037 000

jet pjet pTT>50 GeV |>50 GeV |<2.5<2.5 4545 1010-4-4 Hz Hz 4 5004 500

bb bb X |X ||<2.5|<2.5 6060 1010-4-4 Hz Hz 6 0006 000

bb bb X |X ||<2.5|<2.5 22 1010-4-4 Hz Hz 200200

pp pp ||||<2.5<2.5

1.71.7 1010-4-4 Hz Hz 170170

pp pp J/J/X X ||||<2.5<2.5

11 1010-4-4 Hz Hz 100100

b-jet pb-jet pTT>50 GeV |>50 GeV |<2.5<2.5 0.630.63 1010-4-4 Hz Hz 6363

bb bb J/J/X X ||||<2.5<2.5

0.10.1 1010-4-4 Hz Hz 1010

900 GeV 1029cm-2s-1 rates, statistics


20062006

3030

bb 5 X

bb 53 X

pp+bb J/ (53) X

pp (53) X

Event statistics with B and Quarkonium muonic decays

√√ss =900 GeV, L=1029cm-2s-1

40% machine and data taking efficiency assumed. No reconstruction efficiencies included.


20062006

3131

30% data taking efficiency included.Efficiency of all analysis cuts included.

W e Z ee

√√ss =900 GeV, L=1029cm-2s-1


20062006

3232

Detector configuration Detector configuration during the first physics during the first physics runrun B-layer OK.B-layer OK. ID complete, only TRT C-wheels ID complete, only TRT C-wheels

stagedstaged HLT configuration: full 45kHz HLT configuration: full 45kHz

LVL1 capacity.LVL1 capacity.

atlas first run scenarios for b physics

Documents

lhc commissioning run

atlas bphysics goals

computing commissioning

rich bphysics programme

tevrole of b

run scenarios

new physics effects

lhc operation