1. 111-July-2008ALICE EMCAL PPR Meeting Working Group 4 Summary/Plans Coordinators: J.L. Klay (Cal Poly) and M. Heinz (Yale) Contributing Members: Ken Read (Tennessee) Josh Hamblen (Tennessee) Irakli Martashvili (Tennessee) Ben Rizzo (Creighton) Postdoc (Creighton) Sebastien Gadrat (Grenoble) Brandon Boswell (Cal Poly) Christopher Brown (Cal Poly) (Mostly) Summer “Not available” after 01-Oct-2008 August-November Coordination only after 01-Oct-2008 after 15-August

2. 211-July-2008ALICE EMCAL PPR Meeting Simulations completed for CD-2 Electron, W and B-jet rates (PYTHIA only) Electron and Hadron Background rates (PYTHIA only) –Including photon conversions (full detector included, no reco) Electron track-matching and PID (Full simulation + Full reconstruction) –Efficiency and e/h discrimination Preliminary DVM technique for semi-leptonic decays –Background rejection Preliminary W-jet rejection Reasonably final: Good start, but need more effort: Note: Noise, other sim parameters have changed since CD-2 simulations. We may want to re-do everything with latest version of AliRoot, newer cuts, etc

3. 311-July-2008ALICE EMCAL PPR Meeting Electron rates L=0.5mb -1, 1yr =10 6 s, Pb-Pb scaling ~5000 B-electrons *This plot should be redone Need to double- check that these rates agree with MNR NLO

4. 411-July-2008ALICE EMCAL PPR Meeting Conversion backgrounds <10% convert before TRD/TOF R~428cm Start of EMCAL: (~20% reduction) Track-matching cut eliminates these

5. 511-July-2008ALICE EMCAL PPR Meeting Electron/Hadron Ratios Need a minimum factor of 400 hadron rejection *This plot should be redone

6. 611-July-2008ALICE EMCAL PPR Meeting Track-Cluster matching ~90% track-cluster matching efficiency Matched particles (mostly hadrons) *Should be revisited **Re-check efficiency in PYTHIA and HIJING PYTHIA

7. 711-July-2008ALICE EMCAL PPR Meeting Electron ID: p/E What is the status of testbeam e/h?

8. 811-July-2008ALICE EMCAL PPR Meeting Electron ID: summary For p T >10 GeV/c, pion rejection is well above the factor 400 needed High efficiency *Add a few more efficiency curves? *Should be re-done

9. 911-July-2008ALICE EMCAL PPR Meeting B-Jet Rates Expect several hundred 80 GeV B-jets per year Should make annual statistics plot similar to electron rates

10. 1011-July-2008ALICE EMCAL PPR Meeting Displaced Vertex Method The method pursued here has previously been used by CDF to identify secondary vertices from semi-leptonic decays. Breakdown of method: –Find a high-pt electron trigger particle in EMCAL –Pair with all charged hadrons within a cone of radius dR. –Reconstruct “approximate” (average between B-D decay) secondary vertex and apply more cuts to reduce backgrounds from other leptonic decays. –Plot L xy distribution and obtain B- contribution from positive/negative imbalance D0D0 B- e- K  /e P e+K r PrimVtx SecVtx L xy = r.p e+k / |p e+k | L xy CDF Phys.Rev.D66 (2002))

11. 1111-July-2008ALICE EMCAL PPR Meeting Signal vs. Backgrounds Electron p T -cut > 10 GeV/c Min. 6 ITS-hits on both electron/hadron track Inv mass of (elec-kaon) mass > 1.7 GeV Pair DCA < 200  m B-Tag = |L xy | > 600  m Bottom Signal Backgrounds Cuts used for analysis

12. 1211-July-2008ALICE EMCAL PPR Meeting Efficiencies All sources B-jets Dalitz Conversions Charm B-jets More stats needed, higher p T

13. 1311-July-2008ALICE EMCAL PPR Meeting W backgrounds   pTpT pTpT EMCAL Acceptance B-jet electronsW electrons So far only a qualitative look ~10x higher stats

14. 1411-July-2008ALICE EMCAL PPR Meeting DVM Comparison: B-jet vs W B-jetsW Standard cuts Standard cuts + M inv > 1.7 GeV (charm rejection) Standard cuts + M inv > 1.7 GeV + Max ITS-hits Blue = right - left More statistics needed

15. 1511-July-2008ALICE EMCAL PPR Meeting DVM results After applying DVM cuts the signal efficiency is ~30-40%, whereas the backgrounds are factor ~100 suppressed. Electrons from all sources (before DVM method) Electrons from all sources (after DVM method)

16. 1611-July-2008ALICE EMCAL PPR Meeting What’s needed for PPR Revisit rate calculations with higher statistics Re-check e-ID with newer AliRoot Electron and Electron-Jet Trigger –Rates and backgrounds? Electron Spectra/R AA studies –Investigate electron  heavy meson (Charm/Bottom) correspondence in AA –Compare to TPC alone and TPC+TRD vs. with EMCAL D/B Spectra/R AA studies –DVM method for B-mesons through e+D –Displaced vertex reconstruction of B through J/psi+K –Compare to electron R AA B-jet studies –DVM B-jet selection Effect of mis-identified electron/hadrons? –W rejection –Study of alternative tagging methods/algorithms –Combine DVM method and electron ID with JETAN Cone and FastJet objects FF performance for B-jets Effect of mis-identified B-jets on FF Effect of mis- identified electron/hadrons?

17. 1711-July-2008ALICE EMCAL PPR Meeting Preliminary work matrix TaskToolsManpowerStatistics Revisit rates (higher stats) PYTHIA + Material -- -kinematics info 0.5 person100k x 15 jet p T bins Re-check e-ID (track-matching, p/E) PYTHIA/HIJING + Full simulation 0.5 person Single e,  0 10k x ~10 p T ranges 100k x 15 jet p T bins + 10k HIJING bkg Electron and E-Jet trigger (rates/bkg) PYTHIA/HIJING + AliEMCALTrigger, HLT Trigger Group? 100k x 15 jet p T bins + 10k HIJING bkg Electron spectra/R AA (e  B/D corresp., compare to TPC and TPC+TRD) PYTHIA + Full simulation 1 person100k x 15 jet p T bins 100k x ~5 p Thard bins each of MSEL4 and MSEL5 D/B Spectra/R AA (e+D, J/Psi+K, mis-ID) PYTHIA + Full simulation 1-2 people100k x 15 jet p T bins 100k x ~5 p Thard bins each of MSEL4 and MSEL5 B-jets (DVM,W,JETAN reco, FF, other tag methods) PYTHIA/HIJING + Full simulation 2-3 people100k x ~5 p Thard bins each of MSEL4 and MSEL5 50-100k W-boson decays 10k HIJING bkg

18. 1811-July-2008ALICE EMCAL PPR Meeting ALICE Grid resources available PDC08 simulations used a few different AliRoot versions –http://pcalimonitor.cern.ch/job_details.jsphttp://pcalimonitor.cern.ch/job_details.jsp –EMCAL was in for all of these runs –At Offline week we were encouraged to submit requests CPU is not a problem Storage for our files is the major issue –Do we have grid-accessible space at pdsf/LLNL? v4-11-Rev-02 v4-10-Rev-02 v4-11-Rev-02 v4-12-Rev-02 v4-13-Rev-02