The ALICE EMCal The ALICE EMCal Physics Performance ReportPhysics Performance Report

- Status -- Status -

Rene BellwiedRene Bellwied

(Wayne State University)(Wayne State University)

EMCal Collaboration Meeting, Nantes, July 16EMCal Collaboration Meeting, Nantes, July 16 thth, 2008, 2008

Purpose of the documentPurpose of the document

Originally requested by the Department of Originally requested by the Department of Energy and to be completed by Dec.31Energy and to be completed by Dec.31stst, , 2008, in order to formulate the physics scope 2008, in order to formulate the physics scope of the U.S. contribution to ALICE.of the U.S. contribution to ALICE.

Based on discussions with ALICE the EMCal Based on discussions with ALICE the EMCal PPR will become an official addendum to the PPR will become an official addendum to the existing ALICE PPR.existing ALICE PPR.

It will also serve as a reference for the It will also serve as a reference for the upcoming EMCal Technical Design Reportupcoming EMCal Technical Design Report

OrganizationOrganization Report coordinator: Rene Bellwied (Wayne State)Report coordinator: Rene Bellwied (Wayne State) Six prioritized sub groups with group coordinatorsSix prioritized sub groups with group coordinators

1.) jet reconstruction (Joern Putschke)1.) jet reconstruction (Joern Putschke)2.) EMCal triggering (Mateusz Ploskon)2.) EMCal triggering (Mateusz Ploskon)3.) photons and gamma jets (Gustavo Conesa Balbastre)3.) photons and gamma jets (Gustavo Conesa Balbastre)4.) electron and heavy quark tagging (Mark Heinz / Jennifer Klay)4.) electron and heavy quark tagging (Mark Heinz / Jennifer Klay)5.) particle identified jet measurements (Rene Bellwied)5.) particle identified jet measurements (Rene Bellwied)6.) jet correlations (Claude Pruneau)6.) jet correlations (Claude Pruneau)

Initially groups 1 and 6 will be merged until the jet Initially groups 1 and 6 will be merged until the jet reconstruction algorithm is optimized.reconstruction algorithm is optimized.

Bi-weekly EVO meetings.Bi-weekly EVO meetings. Several face-to-face meetings planned around ALICE weeks, Several face-to-face meetings planned around ALICE weeks,

ALICE-US collaboration meetings, EMCal meetingsALICE-US collaboration meetings, EMCal meetings Temporary web-page: Temporary web-page:

http://pdsfweb01.nersc.gov/~bellwied/emcal-ppr.html Report to PWG-3, PWG-4 and ALICE Physics Board regularly Report to PWG-3, PWG-4 and ALICE Physics Board regularly

(either the group coordinators or the report coordinator)(either the group coordinators or the report coordinator)

Working groupsWorking groups

Presently 37 members, almost evenly Presently 37 members, almost evenly distributed over the groups, with priority to the distributed over the groups, with priority to the first four groups.first four groups.

Contributors from 14 institutions:Contributors from 14 institutions: Yale, LBNL, Nantes, Wayne State, Grenoble, Yale, LBNL, Nantes, Wayne State, Grenoble,

CERN, Jyvaskyla, ORNL, Tennessee, Creighton, CERN, Jyvaskyla, ORNL, Tennessee, Creighton, Purdue, UT Austin, LLNL, FrascatiPurdue, UT Austin, LLNL, Frascati

General strategyGeneral strategy

For jet reconstruction, triggering, photon, and For jet reconstruction, triggering, photon, and electron (heavy flavor jet) physics improve on electron (heavy flavor jet) physics improve on the existing simulations as shown in the CD-2 the existing simulations as shown in the CD-2 final physics report.final physics report.

For particle identified jet measurements and jet For particle identified jet measurements and jet correlations develop a performance report and correlations develop a performance report and interface with multiple other detector 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-sidefragmentation on the away-side

Main goals for group 1: jet reconstructionMain goals for group 1: jet reconstruction

Attempt to extend the reliability of jet finding algorithm to jet Attempt to extend the reliability of jet finding algorithm to jet energies below 100 GeV. Important for single jets, crucial for jet energies below 100 GeV. Important for single jets, crucial for jet correlations.correlations.

Optimize jet finding algorithm through comparison (kTJet, JetAn, Optimize jet finding algorithm through comparison (kTJet, JetAn, FastJet)FastJet)

Optimize quenching simulations, estimate effects elliptic and radial Optimize quenching simulations, estimate effects elliptic and radial flow, hadron corrections, electron conversions, jet-energy flow, hadron corrections, electron conversions, jet-energy correctioncorrection

see Peter Jacob’s talksee Peter Jacob’s talk

Main goals for group 2: jet triggeringMain goals for group 2: jet triggering

Attempt to extend the trigger efficiency for jet energies of 50-Attempt to extend the trigger efficiency for jet energies of 50-100 GeV. Check effect of jet quenching100 GeV. Check effect of jet quenching

Optimize LVL-1 algorithm by taking altering patch Optimize LVL-1 algorithm by taking altering patch size/geometry based on new mapping manipulations size/geometry based on new mapping manipulations (elelctronics).(elelctronics).

Optimize HLT through implementation of EMCal software Optimize HLT through implementation of EMCal software and subsequent merging with TPC, TRD and ITS information. and subsequent merging with TPC, TRD and ITS information.

Main goals for group 3:Main goals for group 3:direct photons and gamma-jetsdirect photons and gamma-jets

Optimize Optimize //00 discrimination for direct photon and discrimination for direct photon and -jet -jet measurement (shower shape, isolation cut studies)measurement (shower shape, isolation cut studies)

-jet tagging in PHOS and EMCal down to E-jet tagging in PHOS and EMCal down to E=20-30 GeV in =20-30 GeV in

order to extract reliable FF on away side.order to extract reliable FF on away side.

see Gustavo’s talksee Gustavo’s talk

Isolation cut study, PbPbquenched

Main goals for group 4:Main goals for group 4:heavy quark tagging with electronsheavy quark tagging with electrons

Show electron to heavy meson correspondence in AA collisions. Show electron to heavy meson correspondence in AA collisions. Optimize e/h discriminationOptimize e/h discrimination

Simulate signed DCA method for B-mesonsSimulate signed DCA method for B-mesons Physics: e, B (J/Physics: e, B (J/+K or e+D) spectra, R+K or e+D) spectra, RAAAA, B-jets, B-jets

see Mark Heinz’s talksee Mark Heinz’s talk

Main goals for group 5:Main goals for group 5:particle identified jet measurementsparticle identified jet measurements

Correlate high momentum PID measurements (rdE/dx and V0 Correlate high momentum PID measurements (rdE/dx and V0 method) to triggered jet rates for single hadron or resonance and di-method) to triggered jet rates for single hadron or resonance and di-hadron correlation measurements in jets and between di-jets.hadron correlation measurements in jets and between di-jets.

Determine fragmentation fnunctions for rare hadrons and particle Determine fragmentation fnunctions for rare hadrons and particle ratios (baryon/meson or particle/antiparticle) in jets in EMCal ratios (baryon/meson or particle/antiparticle) in jets in EMCal enhanced data samples and compare to quenching model predictions.enhanced data samples and compare to quenching model predictions.

Main goals for group 6: jet correlationsMain goals for group 6: jet correlations

Simulate possibility of acoplanarity and jet shape Simulate possibility of acoplanarity and jet shape measurements based on jet reconstruction resolution.measurements based on jet reconstruction resolution.

Compare jet axis correlations to leading particle Compare jet axis correlations to leading particle correlations.correlations.

di-jet angle di-jet energy correlation di-jet energy balance

Example for Groups 3/5/6: Example for Groups 3/5/6: physics on the EMCal triggered away-sidephysics on the EMCal triggered away-side

High momentum resonances in jets to determine chirality High momentum resonances in jets to determine chirality (C. Markert, RB, I. Vitev, arXiv:0807.1509)(C. Markert, 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

Next steps

Collect work plans coming in (see next slides)

Collect simulation requests coming in (see next slides)

Obtain more physics-based Jet MC e.g. JEWEL

Example: work plan group 3 (Gustavo) Task Sub Task Who

PID Re-evaluate PID parameters with last AliRoot version

SUBATECH, 1 person

Re-study the g/p0 discrimination SUBATECH, 1 person

EMCAL (gamma) - Central barrel (conversion) combination for Inv, Mass of p0 (not for PPR?)

1 person

Direct photons

Isolation cut

Re-evaluate IC with larger amount of events, specially jet-jet, PYTHIA

Gustavo

Compare predictions for different generators and theory

1 person

Decay photon subtraction with Invariant Mass 1 person

Gamma-jet Improve HI background rejection 1 person

Estimate effect of jet-jet contamination 1 person

Code implementation in Analysis Frame Gustavo

Example: work plan group 4 (Jennifer)Task Tools Manpower StatisticsRevisit rates

(higher stats)

PYTHIA + Material ---kinematics info

0.5 person 100k x 15 jet pT bins

Re-check e-ID (track-matching, p/E)

PYTHIA/HIJING + Full simulation

0.5 person Single e, 0 10k x ~10 pT ranges

100k x 15 jet pT bins + 10k HIJING bkg

Electron and E-Jet trigger

(rates/bkg)

PYTHIA/HIJING + AliEMCALTrigger, HLT

Trigger Group?

100k x 15 jet pT bins + 10k HIJING bkg

Electron spectra/RAA

(eB/D corresp., compare to TPC and TPC+TRD)

PYTHIA + Full simulation

1 person 100k x 15 jet pT bins

100k x ~5 pThard bins each of MSEL4 and MSEL5

D/B Spectra/RAA (e+D, J/Psi+K, mis-ID)

PYTHIA + Full simulation

1-2 people 100k x 15 jet pT bins

100k x ~5 pThard bins each of MSEL4 and MSEL5

B-jets (DVM,W,JETAN reco, FF, other tag methods)

PYTHIA/HIJING + Full simulation

2-3 people 100k x ~5 pThard bins each of MSEL4 and MSEL5

50-100k W-boson decays

10k HIJING bkg

Example Simulation requestsExample Simulation requests

Ideally with AliRoot and through the GRID Group 2

5-200 GeV jet energy spectrum pp and PbPb statistics for each of the bins remains to be determined 10% of planned running year statistic would be comfortable

Group 3 pp exists so mostly PbPb Gamma (EMCAL/PHOS) – jet (quenched, not quenched jet-jet (quenched/not quenched) A couple of quenching scenarios? q= 20 and q=50, models

PQM, PYQUEN, maybe JEWEL? Group 4

see work plan

SummarySummary

A dedicated effort to define the physics scope A dedicated effort to define the physics scope enhancement due to the EMCal in ALICE is underway. enhancement due to the EMCal in ALICE is underway.

We hope to complete the document within six months in We hope to complete the document within six months in close collaboration with the existing PWG’s in ALICE.close collaboration with the existing PWG’s in ALICE.

Any input, comments, suggestions, help is much Any input, comments, suggestions, help is much appreciated.appreciated.