EMCal PPR Group 4 – Electrons/Heavy Flavor-Jets Coordinators: J.Klay (Calpoly), K.Read (Tennessee), M. Heinz (Yale) Group Members: Josh Hamblen & Irakli Martashvili (Tennessee) Udara Abeysekara (Creighton) Alberto Lozea (USP-Sao Paolo) Brandon Boswell & Christopher Brown (Cal Poly) Per Thomas Hille & Student (Yale) Mauro Cosentino (Campinas) Weekly EVO meetings organized by Ken: Thursdays 11:00am EDT C.) Electron and heavy flavor jet reconstruction Electron reconstruction Electron-jet reconstruction Heavy quark energy loss Heavy quark fragmentation functions

Heavy quark tagging with electrons Show electron to heavy meson correspondence in AA collisions. Optimize e/h discrimination Simulate signed DCA method for B-mesons Direct reconstruction of high pT J/

Issues and Updates Electron dE/dx cut AliEn/GRID Software Track-matching bug PWG4 B-jet simulations Plans

Electron ID with dE/dx cut Joern suggested at LBL meeting to look at dE/dx cut for matched tracks when identifying electrons (a la STAR) dE/dx > 70 Single e: All matched tracks PYTHIA: All matched tracks Single e: MC PDG = e PYTHIA: MC PDG = e

AliEn/GRID Since April LBL Meeting We learned that GRID productions unusable Committed new track-matching parameters Continued testing software for running large-scale jobs on grid Current Status Migrated to PWG4 and ALICE Analysis framework Ken Read put together completely working, documented example at /afs/cern.ch/users/k/kread/public/all Ready to validate productions

Track-matching bug Committed new track-matching parameters after LBL meeting Subsequent testing indicated a problem All matches marked as “fake” during reconstruction, thus no matched tracks assigned to clusters “Fake” means MC label of track != MC label of cluster Two different methods for matching exist AliESDtrack + AliESDCaloCluster (post-reconstruction) AliESDtrack + AliEMCALRecPoint (during reconstruction) AliEMCALRecPoint->GetPrimaryIndex() was being used to get the MC label, but should have been AliEMCALRecPoint->GetParents() Bug report and fix submitted to savannah (14-May-09) and patched to release by P. Hristov (15-May-09)

PWG4 Analysis Code As of 14-May-09 all PPR Group 4 members agreed to migrate to PWG4 analysis framework Adheres to ALICE analysis framework Provides much of functionality needed without duplicated effort Cross-section weighting JetFinder correlation integration Interface to various data types Example AliAnalysisTaskElectron provided to group members (JLK) Ken Read adapted example to run in any of 5 modes: Local, LocalCAF, PROOF, GRID, PLUGIN Code tested, documented and available to everyone /afs/cern.ch/users/k/kread/public/all

B-Jet Simulations Recently discovered requested update to AliGenPythia (Oct-08) was not included Previous electron-jet GRID productions not optimized Missing information In order to correlate MC and reconstruction, need to save MC jet info (previously only done for Jet-Jet, -Jet) Incorrect configuration No call to check trigger conditions of requested b-jets In order to improve efficiency, need to require electron with minimum pT in fiducial volume of EMCAL Bug report and fixes submitted (14-May-09) with request for review A. Morsch reviewed fix and responded to add process definition to AliPythia Testing in progress, final fixes imminent

Examples 50 > pThard > 60 pT(e) > 1 GeV in EMCAL

Examples 50 > pThard > 60 pT(e) > 1 GeV in EMCAL

Activities Matrix – group 4 Task Sub-topics/ Physics Plots Manpower 1 Revisit rates (higher stats) 1.1) Electron rates and backgrounds 1.2) B-jet rates and backgrounds 1.3) Hadron rejection requirement E-rates from different sources B-jet rates for electron selection Hadron/electron ratio Jenn 2 Re-check e-ID 2.1) Track-matching in PYTHIA/HIJING 2.2) p/E cut study 2.3)  rejection vs. pT for given efficiency levels Matching efficiency + Fakes p/E example distributions Rejection vs. efficiency Josh 3 Spectra/RAA (single electrons) 3.1) Investigate heavy flavor production via non-photonic electron measurement – Cross-check with NLO predictions 3.2) Investigate HF suppression in heavy ion collisions via R_AA (parton suppression) Electron Spectra in p-p Collisions for PID with: (1) TPC, (2) TPC+TRD, (3) TPC+TRD+EMCAL Electron Spectra in Pb-Pb (Hijing) Collisions for PID with: (1) TPC, (2) TPC+TRD, (3) TPC+TRD+EMCAL Inclusive electrons vs non-photonic electrons Irakli + Ken Task Sub-topics/ Physics Plots Manpower 4 B-jets 5.1) Event-by-Event B-tagging (using Jet-Finder + Displaced Vertex Method (DVM)) 5.2) Event-by-Event B-tagging (using Jet-Finder + Transverse IP significance) 5.3) Measurement of B-jet Fragmentation function (statistical using Jet-Finder + tagging algorithm) B-jet efficiency and false identification rate vs. pT for DVM, other tag methods Rejection rates for non-B-jet vs. pT for DVM, other tag methods B-jet Fragmentation Function sensitivity for various Jet-reco algorithms in p+p 5.1) Jenn, Brandon, Chris 5.2) Alberto & Mauro 5.3) Yale, Udara

Plans Added task to matrix: J/  ee in EMCAL (Mauro Cosentino) Continue developing code within PWG4 framework Working with HFE (heavy flavor electron) group led by Silvia Masciocchi from PWG3 to make sure we coordinate effort/don’t duplicate work Analyze grid data when available Produce final PPR plots