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Working Group 5:Working Group 5:Particle Identified Studies in JetsParticle Identified Studies in Jets

- Status / Plans (July 23- Status / Plans (July 23rdrd, 2008) -, 2008) -

Group Coordinator: Rene Bellwied (WSU)Group Coordinator: Rene Bellwied (WSU)

Group Contributors:Group Contributors:Christina Markert (UT Austin)Christina Markert (UT Austin)

Helen Caines (Yale)Helen Caines (Yale)Franco Riggi’s group (Catania)Franco Riggi’s group (Catania)

ALICE input: M.Ivanov, A.Klaweit, B. HippolyteALICE input: M.Ivanov, A.Klaweit, B. Hippolyte

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Purpose of group 5Purpose of group 5 The purpose is more limited than for groups 1-4The purpose is more limited than for groups 1-4

For particle identified jet measurements and For particle identified jet measurements and correlations develop a small chapter in PPR based correlations develop a small chapter in PPR based on interface with multiple other detector on interface with multiple other detector components in ALICE (TPC,TRD, ITS, PHOS). components in ALICE (TPC,TRD, ITS, PHOS).

Use EMCal as tag on same side and measure Use EMCal as tag on same side and measure fragmentation on the away-side, similar to the fragmentation on the away-side, similar to the physics plots from physics plots from -jet studies. Potentially results -jet studies. Potentially results could be merged with results from group 3 and 6.could be merged with results from group 3 and 6.

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General strategyGeneral strategy

Determine yields for identified hadrons from Determine yields for identified hadrons from PYTHIA based simulations.PYTHIA based simulations.

Fold high momentum yields with jet cone Fold high momentum yields with jet cone parameters and reconstruction efficiencies parameters and reconstruction efficiencies based on simulation of non-EMCal detector based on simulation of non-EMCal detector components.components.

Show quality of particle identified fragmentation Show quality of particle identified fragmentation functions (unquenched and quenched (based functions (unquenched and quenched (based on Sapeta/Wiedemann)on Sapeta/Wiedemann)

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Input from ALICEInput from ALICE V0 & heavy quark reconstruction efficiencies V0 & heavy quark reconstruction efficiencies

and resolution from ITS/TPC studies (Boris and resolution from ITS/TPC studies (Boris Hippolyte et al. (IReS), A.Dainese et al. (INFN))Hippolyte et al. (IReS), A.Dainese et al. (INFN))

rdE/dx high prdE/dx high pTT resolution from TPC for resolution from TPC for ,K,p ,K,p (Marian Ivanov (CERN), Alexander Kalweit (Marian Ivanov (CERN), Alexander Kalweit (GSI))(GSI))

Show quality of particle identified fragmentation Show quality of particle identified fragmentation functions (unquenched and quenched (based functions (unquenched and quenched (based on Sapeta/Wiedemann)on Sapeta/Wiedemann)

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ALICE @ Startup

Configuration

PID Capabilities

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Specific Detector Capabilitiesfor hadron reconstruction

rdE/dx in TPC separation out to 50 GeV/c ? potentially superior to STAR-TPC because of better quoted

dE/dx resolution (6% instead of 8%). But still simulation ! see next page

TOF separation out to 1.4 GeV/c

HMPID (RICH, 2 o’clock position, opposite PHOS, next to EMCal)

/K out to 3 GeV/c, K/p out to 5 GeV/c

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Combine TPC and TRD information

STAR method: at high momentum estimate K+ contribution from reconstructed K0

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Identified heavy quark mesons and V0’s based on ITS and TPC

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Hadron production modelHadron production model(Sapeta / Wiedemann)(Sapeta / Wiedemann)

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Resonance studies Resonance studies (detection through invariant mass (detection through invariant mass reconstruction (only limited reliance on PID))reconstruction (only limited reliance on PID))

Resonance production model (CM, RB, I.Vitev, arXiv:0807.1509)Resonance production model (CM, RB, I.Vitev, arXiv:0807.1509) Determine enhancement factors due to jet trigger and analysis Determine enhancement factors due to jet trigger and analysis

improvements due to jet reconstructionimprovements due to jet reconstruction

Formation time of high pT resonancesMeasure modified resonance in away-side jet

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What we have Hadron yields Resonance

yields

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Strategy Determine statistics and resolution of identified particle

measurements in away-side jet cone (non EMCal info) under EMCal trigger assumption. Measure fragmentation functions and form hadron ratios.

Compare to models: Recombination: L. Maiani et al. (hep-ph/0606217) Quenched Fragmentation: Sapeta/Wiedemann

(arXiv:0707.3494)

For resonances: Determine statistics and resolution in quadrants

(arXiv:0807.1509)

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Triggered jet yields in one LHC year

Another factor 5 is possible by triggering TPC at 500 Hz instead of 100 Hz and using EMCal L1/HLT to cut recorded rate down to 100 Hz (P. Jacobs)

Jet yield in 20 GeV bin

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Work Plan Group 5

Task Sub Task Who

PID Get ALICE input on HMPID, rdE/dx, TRD simulations (resolution, reco.eff.)

1 person from TPC,

1 person from TRD

Put together a ALIRoot or standalone based analysis that combines EMCal and ITS/TPC/TRD info

Rene, Helen

Determine PID FF in jet cone with and without quench (based on PYQUEN)

1 person, input from group 1

Resonances Evaluate resonance reconstruction efficiencies with TPC

1 person (Catania)

Determine significance in quadrant analysis Christina

Trigger Fold jet enhancement factors with PID spectra 1 person, input from group 2

Model comparisons

Run Wiedemann PID quench code if available otherwise compare to estimates in paper

Rene, Christina

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Example Simulation requestsExample Simulation requests

Ideally with AliRoot and through the GRID turning on EMCal, ITS, TPC, TRD (PID code has been recently submitted to AliRoot trunk).

Realistically use jet reconstruction efficiencies from group 1 and fold with PYTHIA spectra and with PID reconstruction efficencies from various other ALICE detectors.

Group 5 request 5-200 GeV jet energy spectrum in pp and PbPb (in bins) 10% of planned running year statistics Compare unquenched and quenched scenario (ideally on basis

of new Wiedemann event generator).