Electron identification M. Jaffré LAL Orsay Outline : L1 and L2 EM objects, L3 tools EMReco algorithms (new from preco05) Energy, position corrections Match with PS and track H-matrices, Likelihood Performances with Zee events SEMReco algorithm EMAnalyze Ntuple Calibration Workshop Sep 25, 2000 M.Jaffré

Mrinmoy Bhattacharjee L1 & L2 major challenges Input Rate to L1 ~ 7.6MHz at 1032cm-2s-1 <pT> e- for J/ee- <pT> e- for W,Z,top decays ~ 2.7 GeV/c central ~ 30-40GeV/c ~ 3.1 GeV/c forward Although threshold high Low threshold in CAL high QCD rate S/B ~ 1/50,000 Calibration Workshop Sep 25, 2000 M.Jaffré

Definition of EM object (e-/) Central Region e = CFT trk + CPS cluster + CCEM Trigger Tower  = No Trk + CPS cluster + CCEM Trigger Tower Forward Region e = MIP + FPS cluster + ECEM Trigger Tower  = No MIP + FPS cluster + ECEM Trigger Tower Calibration Workshop Sep 25, 2000 M.Jaffré

L1 electron algorithm (high pT) Central (1.6) 1 CPS cluster  high matched to 1 track 5GeV/c in 4.50 1 Calo EM tower  7-10GeV (1.6) matched to CPS cluster by quadrant Forward (1.62.6) 1 FPS cluster  high + MIP confirmation 1 Calo EM tower  7-10GeV (1.62.6) matched to FPS cluster by quadrant Track/MIP matching to PS optional; perform only if rates high  1.0 Cal EM>7GeV Calibration Workshop Sep 25, 2000 M.Jaffré

L1 EM trigger rates (high pT) Rates at L=21032cm2/s Cluster/Track & CCAL Quadrant match Cluster & ECAL Quadrant match CEM(1,10,C) 200 W mass, QCD  CEM(1,7,C)CEQ(1)TNQ(1) 62 QCD  CEM(1,10,C)TEL(1,5) 3 W mass, WZ  CEM(1,10,N/S) 690 EC W mass CEM(1,10,N/S)FQN(1) 400 FWD EM CEM(1,10,N/S)FPQ(1) 200 EC W mass Rates highly dependent on thresholds in CAL Quadrant matching give 2-4 in rates rejection 1.0 Calibration Workshop Sep 25, 2000 M.Jaffré

L2 EM triggers Advantages at L2 are: (1) Large decision time 100sec (2) Finer detector information available -- clustering in PS -- clustering in CAL (3) Due to more time finer matching can be performed -- L1 CAL/PS matching in quadrant -- L2 CAL/PS match within 0.20.2 in  Calibration Workshop Sep 25, 2000 M.Jaffré

L2 CAL Preprocessor L1 EM Trigger based on following reference set Marc Buehler L2 CAL Preprocessor L1 EM Trigger based on following reference set 2.5, 5, 7 & 10 GeV ET (1) L2 uses TT’s above low threshold ref. set (2) Find 2nd. Maximum in 33 around seed (3) ETEM = ETEMseed + ET2nd > Thr (4) EMF = ETEM/(ETEM+ETHAD) (5) TISO =  ET(EM+Had)/ETEM ( 33  - seed ) = ETEM/ET(EM+HAD) (33  includes seed) EMF>0.85 TISO < 0.4 PT =20GeV Calibration Workshop Sep 25, 2000 M.Jaffré

L2 CAL Efficiency, Rates & Timing L1 seed tower 7GeV / 10GeV ETEM  10GeV / 12GeV EMF  0.85 + TISO  0.4 pT 15Gev/c 20GeV/c 32.5GeV/c L2/L1 93.3% 99.5% 100.0% “ 86.0% 100.0% 100.0% Dijet Rates L1(1,7GeV) L2(1,10GeV) L2(1,12GeV) @2E32 900Hz 145Hz 90Hz L2 CAL Timing (available 50sec) L2 Seed cut 0.5GeV 1.0GeV 1.5GeV 2.0GeV # of seeds 77 19 10 7 Time s 179 46 25 18 Calibration Workshop Sep 25, 2000 M.Jaffré

L2 electron algorithm (high pT) Central (1.6) (L2 Global 50sec) 1 CAL tower 7GeV 1 CPS Axial cluster  5MIPs + CFT Track tag CPS 3D match of X,U,V  ,  (1) Axial ,U, V = 5MIPs (2) Axial = 5MIPs & U,V = 3MIPs Different detector info combined at L2 Global CPS-CAL match within 0.250.25 in  (1) efficiency loss for ET <40GeV (Z  ee, 93.7%) (W+Jets, 84.0%) (2) regains lost electrons at low ET (Z  ee, 99.0%) (W+Jets, 95.4%) Calibration Workshop Sep 25, 2000 M.Jaffré

L2 electron algorithm (high pT) Forward (1.62.6) (L2 Global 50sec) CAL Cluster (ETEM)> 10GeV, CAL EMF 0.85 + CAL Isolation  0.4 FPS 3D match of U,V  ,  (1) U, V = high (2) U = high & V = low OR vice versa Different detector info combined at L2 Global FPS, CAL matching within 0.250.25 in  Z  ee 94.3% - 97.5% (HH / HL.OR.LH) @ 21032cm2/s 900Hz 145Hz 80Hz Calibration Workshop Sep 25, 2000 M.Jaffré

B Physics: di-electron trigger L1 & L2 Trigger Performance: Central Region (CAL EM>2.5GeV, CPS>3MIPs) eff (pT>1.5GeV) = 10%, Rates = 50Hz Forward region (CAL EM>2.5GeV, FPS>5MIPs) L1 eff (pT>1.5GeV) = 10%, Rates = 1.0-1.5KHz L2 eff (pT>1.5GeV) = 4-5%, Rates = 50Hz Calibration Workshop Sep 25, 2000 M.Jaffré

L1 & L2 summary L1 Trigger electron (pT>5GeV) efficiency > 95% (7-10GeV CAL) background rates 1.5 Hz (7GeV CAL thr) 200 - 500 Hz (10GeV CAL Thr) di-e (pT>1.5GeV) efficiency ~ 20%(cen), 10%(fwd) background rates 1-2kHz (cen+fwd) PS/CAL Quadrant matching 2-3 in rates L2 Trigger electron (pT>5GeV) efficiency > 95% (10GeV ETEM) background rates 50-100 Hz (10GeV ETEM) di-e (pT>1.5GeV) efficiency ~ 10%(cen),5%(fwd) background rates 100Hz (cen+fwd) CAL EMF, Isolation, Invariant mass helps PS/CAL 0.250.25 in  match = 2-3 in rates Calibration Workshop Sep 25, 2000 M.Jaffré

Volker Buescher Juan Estrada Vishnu Zutshi L3 Components Cal.Unpacker Charles Leggett CPS.Unpacker Andre Turcot FPS Unpack U.Michigan L3TPrVtx G. Lima Cal. Cluster Volker Buescher L3TCps Andre Turcot L3TFps U.Michigan L3TEle, L3TPhoton Volker Buescher Juan Estrada Vishnu Zutshi L3track framework Daniel Whiteson

L3 Preshower Clustering CPS ( A. Turcot ) a review of algorithm performed last summer Algorithm : - contiguous strips above threshold (2 MIPs) clustered in each layer ( Single Layer Cluster ) - 3D matching of SLC with some energy correlation Localized clustering in  or - implemented to be used by L3 electron tool CPS resolution for single e- (r) = 0.54 mm, (z) = 1.9 mm Calibration Workshop Sep 25, 2000 M.Jaffré

EMRECO input cluster Cluster « finding » algorithms 3 Clustering available in calreco based on Towers : simple cone, cone and emNN Default now is simplecone R=0.4 (fast) 4th algorithm based on cells : CellNN Selection of the clustering Since t01.11.00 (  preco05) New parameter in EMReco.rcp “standard” emreco RCP clusterer = <emreco CalScone0401> cellNN clusters RCP clusterer = <cellNN CellNN> Imply different algorithms for building the EMCluster Both could be “called”  2 different Emparticle Chunks Calibration Workshop Sep 25, 2000 M.Jaffré

EMRECO algorithms EMCluster from cellNN clusters Serban Protopopescu M.J. EMRECO algorithms EMCluster from cellNN clusters Ptmin > 1.5 GeV ; e.m. fraction > 90% Cluster in UNCHANGED EMCluster for “standard” emreco Isolation : (Etotal(cone 0.4) - Eem(cone0.2))/ Eem(cone0.2) < 0.2 EMCluster definition (EM1,EM2,EM3,EM4,FH1) CC : all channels in a (3x3) window EC : all channels in a cone of 10 cm radius in EM3 around hottest channel in EM3 RCP parameters rather independent of clustering algorithm for isolated electrons Calibration Workshop Sep 25, 2000 M.Jaffré

EMRECO (cont ’d) EMcluster position corrections (DooKee Cho) CAL cell is given a weight : w=w0 + log(Ecell/Elayer) w0 varies for each layer Additional corrections depending on z and Pt (CC), on r (EC) EMcluster energy corrections (Serban) CPS : 15.0 x ECPS + 0.18 GeV FPS : 15.3 x EFPS Overall correction : E=E/(1.3 –SQRT(0.08+0.4418/E)) DE/E uncorr CPS energy fraction Calibration Workshop Sep 25, 2000 M.Jaffré

Cluster position resolutions DooKee Cho Calibration Workshop Sep 25, 2000 M.Jaffré

EMRECO (cont ’d) Preshower matching Track matching input : PS 3D clusters from cal_reco and fps_reco select the most energetic cluster within a window : x = 0.05x0.05 CPS x = 0.1x0.1 FPS Track matching input : ChargedParticleChunk P>1.5 GeV/c; x window = 0.05x0.05 Window sizes can be reduced without loss of efficiency Emparticle direction and ID 1 - track (if it exists )direction at the vertex electron  12 2 - vertex - CPS cluster direction photon 10 3 - vertex - cluster position in EM3 photon 10 Calibration Workshop Sep 25, 2000 M.Jaffré

HMRECO status It uses the package hmatrix to store/read H-matrix files F.Touze, A. Abdesselam,M.J. (cvs) Package used by emreco to - build different flavours of H-matrices - calculate the covariance parameter 2 as a measure of the compatibility of the EMCluster object with an electron shower The choice between 1 and 2 is done by a RCP parameter in emreco  Emreco provides the same cluster preselection It uses the package hmatrix to store/read H-matrix files Calibration Workshop Sep 25, 2000 M.Jaffré

Available H-matrices in preco04 Run I H matrix (41 parameters) Energy fractions in floors [EM1, EM2,EM4] Energy fractions in floor EM3 (6x6) channels log(Etot),Zvertex/28. H matrix (9 parameters) Energy fractions in floors [EPS,EM1, EM2, EM3,EM4] DETA, DRPHI in floor EM3 log(Etot), Zvertex/28. Exists for 2 energy ranges : < > 30 GeV(RCP parameter)  2 2 values attached to each EM candidate Calibration Workshop Sep 25, 2000 M.Jaffré

Latest results with Hmatrices 30GeV Calibration Workshop Sep 25, 2000 M.Jaffré

EMReco Efficiencies in CC F.Fleuret CC fiducial region CPS fiducial region TRK fiducial region + opposite sign 86% (93% per e) 98% (99% per e) 10K Pythia Zee <1.1>minBias Preco04.00.01 98% (99% per e)

EMReco Efficiencies in EC F.Fleuret EC fiducial region FPS fiducial region TRK fiducial region + opposite sign 67% (82% per e) 92% (96% per e) 10K Pythia Zee <1.1>minBias Preco04.00.01 97% (99% per e)

Serban Calibration Workshop Sep 25, 2000 M.Jaffré

Serban Calibration Workshop Sep 25, 2000 M.Jaffré

Calibration Workshop Sep 25, 2000 M.Jaffré Frédéric Fleuret

Conclusions EMReco provides a framework to identify electrons There is some degree of flexibility RCP parameters Clustering choice SEMReco exists for soft electrons EMAnalyze/SEMAnalyze provides a Ntuple with blocks of data for each choice for an easy comparison Need user feedback Calibration Workshop Sep 25, 2000 M.Jaffré