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Working Group 4 Summary/Plans

Working Group 4 Summary/Plans. Coordination only after 01-Oct-2008. “Not available” after 01-Oct-2008. Coordinators: J.L. Klay (Cal Poly) and M. Heinz (Yale) Contributing Members: Ken Read (Tennessee) Josh Hamblen (Tennessee) Irakli Martashvili (Tennessee) Ben Rizzo (Creighton)

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Working Group 4 Summary/Plans

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  1. Working Group 4 Summary/Plans Coordination only after 01-Oct-2008 “Not available” after 01-Oct-2008 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) August-November after 15-August (Mostly) Summer ALICE EMCAL PPR Meeting

  2. Simulations completed for CD-2 Reasonably final: • 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 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 ALICE EMCAL PPR Meeting

  3. Electron rates *This plot should be redone Need to double-check that these rates agree with MNR NLO ~5000 B-electrons L=0.5mb-1, 1yr =106 s, Pb-Pb scaling ALICE EMCAL PPR Meeting

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

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

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

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

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

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

  10. Displaced Vertex Method /e K Pe+K e- CDF Phys.Rev.D66 (2002)) D0 SecVtx r B- PrimVtx Lxy • 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 Lxy distribution and obtain B-contribution from positive/negative imbalance Lxy= r .pe+k / |pe+k| ALICE EMCAL PPR Meeting

  11. Signal vs. Backgrounds Bottom Signal Cuts used for analysis • Electron pT-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 = |Lxy| > 600 m Backgrounds ALICE EMCAL PPR Meeting

  12. Efficiencies More stats needed, higher pT B-jets B-jets All sources Dalitz B-jets B-jets Charm Conversions ALICE EMCAL PPR Meeting

  13. W backgrounds So far only a qualitative look ~10x higher stats B-jet electrons W electrons pT pT EMCAL Acceptance EMCAL Acceptance h h ALICE EMCAL PPR Meeting

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

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

  16. 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/RAA studies • Investigate electron  heavy meson (Charm/Bottom) correspondence in AA • Compare to TPC alone and TPC+TRD vs. with EMCAL • D/B Spectra/RAA studies • DVM method for B-mesons through e+D • Displaced vertex reconstruction of B through J/psi+K • Compare to electron RAA • 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? ALICE EMCAL PPR Meeting

  17. Preliminary work matrix ALICE EMCAL PPR Meeting

  18. ALICE Grid resources available v4-10-Rev-02 v4-11-Rev-02 v4-10-Rev-02 v4-11-Rev-02 v4-12-Rev-02 v4-13-Rev-02 • PDC08 simulations used a few different AliRoot versions • http://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? ALICE EMCAL PPR Meeting

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