1. 1 Working Group 5: Particle Identified Studies in Jets - Status / Plans (July 23 rd, 2008) - Group Coordinator: Rene Bellwied (WSU) Group Contributors: Christina Markert (UT Austin) Helen Caines (Yale) Franco Riggi’s group (Catania) ALICE input: M.Ivanov, A.Klaweit, B. Hippolyte

2. 2 Purpose of group 5  The purpose is more limited than for groups 1-4  For particle identified jet measurements and correlations develop a small chapter in PPR based on interface with multiple other detector components in ALICE (TPC,TRD, ITS, PHOS).  Use EMCal as tag on same side and measure fragmentation on the away-side, similar to the physics plots from  -jet studies. Potentially results could be merged with results from group 3 and 6.

3. 3 General strategy  Determine yields for identified hadrons from PYTHIA based simulations.  Fold high momentum yields with jet cone parameters and reconstruction efficiencies based on simulation of non-EMCal detector components.  Show quality of particle identified fragmentation functions (unquenched and quenched (based on Sapeta/Wiedemann)

4. 4 Input from ALICE  V0 & heavy quark reconstruction efficiencies and resolution from ITS/TPC studies (Boris Hippolyte et al. (IReS), A.Dainese et al. (INFN))  rdE/dx high p T resolution from TPC for ,K,p (Marian Ivanov (CERN), Alexander Kalweit (GSI))  Show quality of particle identified fragmentation functions (unquenched and quenched (based on Sapeta/Wiedemann)

5. 5 ALICE @ Startup   Configuration   PID Capabilities

6. 6 Specific Detector Capabilities for 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

7. 7 Combine TPC and TRD information STAR method: at high momentum estimate K + contribution from reconstructed K 0

8. 8 Identified heavy quark mesons and V0’s based on ITS and TPC

9. 9 Hadron production model (Sapeta / Wiedemann)

10. 10 Resonance studies (detection through invariant mass reconstruction (only limited reliance on PID))  Resonance production model (CM, RB, I.Vitev, arXiv:0807.1509)  Determine enhancement factors due to jet trigger and analysis improvements due to jet reconstruction Formation time of high p T resonances Measure modified resonance in away-side jet

11. 11 What we have Hadron yieldsResonance yields

12. 12 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)

13. 13 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

14. 14 Work Plan Group 5 TaskSub TaskWho PIDGet 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 ResonancesEvaluate resonance reconstruction efficiencies with TPC 1 person (Catania) Determine significance in quadrant analysisChristina TriggerFold jet enhancement factors with PID spectra1 person, input from group 2 Model comparisons Run Wiedemann PID quench code if available otherwise compare to estimates in paper Rene, Christina

15. 15 Example 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).