Electronsphotons: from detector to Ntuple

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Electrons/photons from detector to Ntuple
M. Jaffré LAL Orsay
Outline L1 and L2 EM objects
L3 electron/photon tools Electron/phot
ons in D0Reco
2
L1 L2 major challenges
Mrinmoy Bhattacharjee

• Input Rate to L1 7.6MHz at 1032cm-2s-1
• 
  
• ltpTgt e- for J/??ee-
  ltpTgt 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

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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
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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 EMgt7GeV
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L1 EM trigger rates (high pT)

• Rates at L2?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
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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 ?????

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L2 CAL Preprocessor
Marc Buehler

• L1 EM Trigger based on following reference set
• 2.5, 5, 7 10 GeV ET
• (1) L2 uses TTs above low threshold ref. set
• (2) Find 2nd. Maximum in 3?3 around seed
• (3) ETEM ETEMseed ET2nd gt Thr
• (4) EMF ETEM/(ETEMETHAD)
• (5) TISO ? ET(EMHad)/ETEM ( 3?3 ? - seed
  )
• ETEM/?ET(EMHAD) (3?3 ? includes seed)

EMFgt0.85
TISO lt 0.4
PT 20GeV
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L2 CAL Efficiency, Rates Timing

• (In 1.6?????2.6)
• 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)
• _at_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

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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 lt40GeV
• (Z ? ee, 93.7)
• (WJets, 84.0)
• (2) regains lost electrons at low ET
• (Z ? ee, 99.0)
• (WJets, 95.4)

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L2 electron algorithm (high pT)

• Forward (1.6?????2.6) (L2 Global 50?sec)
• CAL Cluster (ETEM)gt 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)

_at_ 2?1032cm2/s
900Hz
145Hz
80Hz
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B Physics di-electron trigger

• L1 L2 Trigger Performance
• Central Region (CAL EMgt2.5GeV, CPSgt3MIPs)
• eff (pTgt1.5GeV) 10, Rates 50Hz
• Forward region (CAL EMgt2.5GeV, FPSgt5MIPs)
• L1 eff (pTgt1.5GeV) 10, Rates 1.0-1.5KHz
• L2 eff (pTgt1.5GeV) 4-5, Rates 50Hz

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L1 L2 summary

• L1 Trigger
• electron (pTgt5GeV) efficiency gt 95
  (7-10GeV CAL)
• background rates 1.5 Hz
  (7GeV CAL thr)
• 
  200 - 500 Hz (10GeV CAL Thr)
• di-e (pTgt1.5GeV) efficiency 20(cen),
  10(fwd)
• background rates 1-2kHz
  (cenfwd)
• PS/CAL Quadrant matching ?2-3 in rates
• L2 Trigger
• electron (pTgt5GeV) efficiency gt 95
  (10GeV ETEM)
• background rates 50-100
  Hz (10GeV ETEM)
• di-e (pTgt1.5GeV) efficiency
  10(cen),5(fwd)
• background rates 100Hz
  (cenfwd)
• CAL EMF, Isolation, Invariant mass helps
• PS/CAL 0.25?0.25 in ????? match ?2-3 in
  rates

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Juan Estrada
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
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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

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CPS strip energy
2 MeV
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L3TEle(L3TPhoton)

• List of calorimeter clusters from the
  l3fcalcluster.
• Possibilities
• EMFR cut.
• Calorimeter cluster shape.
• Longitudinal and transverse variables from CPS
• Isolation
• Track matching
• Implemented
• EMFR cut.
• 4x4 Hmatrix (EM1,EM2,EM3,EM4)

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Some plots from L3Tele
Single 20 GeV electrons and pions
Track-Cluster matching in W events
EM fraction
log ?2
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L3 status

• Functional tool exists to do L3 EM trigger.
• Access to calcluster, CPScluster and tracks is
  now possible at L3.
• Studies on the best way to use this variables are
  going on now.

• Efficiency of L3Ele 98 for 50GeV electrons
  with a EMFR cut. Factor of 50 rejection for 50GeV
  pions. (Not realistic, waiting for L2 Ele
  simulation).
• Timing
• L3TEle does not do anything that takes time just
  a few multiplications and a 1D cut
• CalCluster 2msec for a top event
• Unpackers studies pending (NTsystem)

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EMRECO algorithm
Serban Protopopescu M.J.

• Cluster  finding  algorithms
• 3 Clustering coded based on Towers simple cone,
  cone and NN
• Default now is simplecone R0.4 (fast)
• 4th algorithm based on cells CellNN almost ready
  interfaced to EMReco
• Selection of calorimeter clusters
• Ptmin gt 1.5 GeV e.m. fraction gt 90
• Isolation (Etotal(cone 0.4) - Eem(cone0.2))/
  Eem(cone0.2) lt 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

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EC electrons

• Results from D00Kee Cho (Rochester)

99
12.5cm
10cm
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EC electrons

• Results from D00Kee Cho (Rochester)

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EMRECO (cont d)

• EMcluster position corrections (DooKee Cho)
• CAL cell is given a weight ww0
  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
• EE/(1.3 SQRT(0.080.4418/E))

DE/E uncorr
CPS energy fraction
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Cluster position resolutions
DooKee Cho
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EMRECO (cont d)

• Preshower 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
• Pgt1.5 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

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HMRECO status
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

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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 lt gt 30 GeV(RCP
  parameter)
• ? 2 ?2 values attached to each EM candidate

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Latest results with Hmatrices
L09
H09
H41
L41
30GeV
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Electron Likelihood
ISNGrenoble (S.Crepé,.. )
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E/p electron distributions
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EM ID using Neural network
Dhiman Chakraborty Supriya Jain Vishnu Zutshi
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NN vs H-matrix
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Generation of EM fake samples

• Principle is to select at the generator level
  jets which have a high probability to give a e/?
  fake at the RECO level without biasing the fake
  samples
• Nirmalya Parua (ISNG) electron fakes
• ISAJET QCD events with em fraction gt 0.65
• high
  PT track gt 1 GeV/c within
• 0.1
  in (?,?) and PTjet / PTtrack lt 5
• Production at CCIN2P3(Lyon) has started
• Alex Menilchouk (Brown) electron/photon fakes
• Pythia QCD events with a leading ?0 or ?
  (or 2 ?) and
• (Etotal(0.4)-EEM(0.2))/EEM(0.2) lt 2
• ETEM(0.2) gt 6. GeV

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Efficiencies mb1.1av
F.Fleuret
CCCC events PYTHIA
WITHOUT EDGES
1. lt Detect. h
100
0) MC events
99 (.992)
1) after EM selection
2) after EM sel. PS matching
97 (.982)
3) after EM sel. PS match. TRK match.
84 (.922)
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Efficiencies mb1.1av
F.Fleuret
ECEC events PYTHIA
1.9 lt Detect. h lt 2.5
100
0) MC events
91(.952)
1) after EM selection
2) after EM sel. PS matching
75(.872)
3) after EM sel. PS match. TRK match.
27(.522)
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Conclusions

• D0 can trigger on electrons at high PT as well as
  on di-electrons of low PT
• Using calorimeter, PS and tracker electrons will
  be identified, and measured with high efficiency
• Vertical Review Committee recognized that
• The EM ID group has done a lot of very
  good work so far
• BUT still a lot of work to do ..
• !!!!!!!! physics groups should not weaken the
  effort in the object ID groups