TWiki> Main Web>TWikiUsers>PasqualeMusella>PmWgammaCoupling>PmWgammaWGammaReco (2008-10-23, PasqualeMusella) EditAttachPDF

W gamma reconstruction and selection study

Last update 16 Oct 2008

Samples

Signal

sample generator $N_{etvs}$ $\hat{p_T}_{min}$ $\sigma \times B.R.$ k-factor generator level cuts acceptance $\sigma \times B.R. \times k \times A$
$W(\mu \nu)\gamma$ pythia 130000 5 GeV 40 2 $p_T(\mu) > 3GeV \\ -2.7 < \eta(\mu) < 2.7 \\ p_T(\gamma) > 10GeV \\ -2.7 < \eta(\gamma) < 2.7 \\ p_T(\nu)>20$ 19.8% 16 pb

Background

sample generator number of (unweighted)
events 		production cross section (pb)
W + (0-7) jet alpgen 821855 CSA07Muon-Chowder 58E+3
Z + (0-7) jet alpgen 2656908 CSA07Muon-Chowder 5.7E+3
tt + (0-4) jet alpgen 293455 CSA07Muon-Chowder 836.5
Gamma + Jets pythia 5435 CSA07Muon-Gumbo 1.7E+8
QCD pythia 112068 CSA07Muon-Gumbo 2.3E+9
Minbias pythia 11080 CSA07Muon-Gumbo 8E+10

Trigger and Reconstuction

  • The reconstruction of both signal and background samples were performed with the detector conditions expected for 100pb-1.
  • The path considered for the HLT trigger was the 1IsoMuon.

  • Notes
    • All the plots are normalized to 1fb-1.
    • The effect of the trigger on the signal is not yet included.

W reconstruction

  • Require globally reconstructed isolated muon + Missing Energy
  • Require transverse mass of the muon + MET system to be consistent with the W transverse mass
    $ p_{T}(\mu) > 20 GeV$
    $-2< \eta(\mu) < 2$
    $ traker Iso (\mu) < 3 GeV $
    $ m_{T}(\mu,\displaystyle{\not}{E}) > 60 GeV$

  • $ p_{T}(\mu) $

  • $m_{T}(\mu,\displaystyle{\not}{E})$
    wMt_distribs.png mT.png

Second Muon/Z Veto

  • Reject events with more than one globalMuons with $p_{T} > 20 GeV$
  • Reject if the invariant mass of standaloneMuons pairs $m(\mu^{+},\mu^{-}) > 10 GeV$

  • $N(global \mu; pT > 20 GeV)$
    nZVetoMu_distribs.png muVeto.png

  • $m(standalone \mu^{+} \mu^{-})$
    zToMuMusMass_distribs.png zVeto.png

Photon selection

  • Minimum pt
  • Fiducial region
    $p_T(\gamma) > 10 GeV$
    $ \mid \eta \mid < 1.479 ~ \cup \mid eta \mid > 1.579 ~ \cap \mid eta \mid <2.4$

Photon Id

  • Cut-based photonId
    • $tkIso(r,R) := \sum_{r < \Delta R < R} ~ p_{T}(track)$
    • $ecalIso(R) := \sum_{\Delta R < R} ~ E_{T}(rechit) - E_{T}(\gamma)$
    • $hcalIso(R) := \sum_{\Delta R < R} ~ E_{T}(tower) $
    • $\sigma_{\eta\eta} := $

  • Barrel
    $tkIso(0,0.40) < 4 GeV$
    $ecalIso(0.35)/ E_{T}(\gamma) < 0.092 $
    $hcalIso(0.45)/ E_{T}(\gamma) < 0.066$
    $\sigma_{\eta\eta} < 0.0096$

  • Endcap
    $tkIso(0,0.40) < 4 GeV$
    $ecalIso(0.35)/ E_{T}(\gamma) < 0.115$
    $hcalIso(0.45)/ E_{T}(\gamma) < 0.116$
    $\sigma_{\eta\eta} < 0.0262$

  • Photon spectrum
    After Photon selection and ID
    photonId.png

Wgamma kinematics

  • Require a minimal separation between the photon and the muon.
  • Require the transverse mass of the muon-gamma-MET system to be compatible with the Wgamma production.
    $\Delta R(\mu,\gamma) > 1.5$

  • $\Delta R(\mu,\gamma)$
    muGammaDeltaR_distribs.png deltaR.png

Jet Veto

  • Few variables were tried as jet-veto variables
  • No more than two jets above 42 GeV
    $p_T(jet_2) < 30 GeV$

  • $p_T(jet_2)$
    jet2Pt_distribs.png jetVetoCut.png

Event yield summary

jetVeto 1439 52 172 2536 0.522 1.92
W g tt X Z X W X S / B B / S
HLT 16000(w/o HLT) 60776 1246850 7964570 N.A. N.A.
muSel 10424 50594 941132 6224210 0.001 692.23
mT 7705 29959 198174 4085110 0.002 559.76
muVeto 7704 25957 145518 4083800 0.002 552.33
zVeto 7677 22805 136064 4068020 0.002 550.6
photon Sel and ID 2186 1849 321 6125 0.264 3.8
deltaR 1828 1377 262 3421 0.361 2.77

Background Estimation

TODOs

  • Check the effect of the trigger on the signal.
  • Include QCD, Photon+Jet and Minimum Bias in the backgrounds.
Attachments Attachments
Topic attachments
I Attachment History Action Size Date Who Comment
PNGpng PhotonIdTw_Barrel.png r2 r1 manage 20.7 K 2008-08-15 - 18:19 PasqualeMusella W gamma vs W jet Barrel
PNGpng PhotonIdTw_Endcap.png r2 r1 manage 20.3 K 2008-08-15 - 18:20 PasqualeMusella W gamma vs W jet Endcap
PNGpng PhotonPt_AfterId.png r1 manage 8.7 K 2008-08-15 - 18:58 PasqualeMusella W gamma vs W Njet after PhotonId cuts
PNGpng deltaR.png r3 r2 r1 manage 23.1 K 2008-10-16 - 19:37 PasqualeMusella  
PNGpng jet1Pt_distribs.png r1 manage 32.2 K 2008-10-02 - 19:15 PasqualeMusella  
PNGpng jet2Pt_distribs.png r2 r1 manage 19.6 K 2008-10-16 - 19:45 PasqualeMusella  
PNGpng jet3Pt_distribs.png r1 manage 30.2 K 2008-10-02 - 19:16 PasqualeMusella  
PNGpng jetVetoCut.png r2 r1 manage 22.9 K 2008-10-16 - 19:39 PasqualeMusella  
PNGpng mT.png r3 r2 r1 manage 20.2 K 2008-10-16 - 19:42 PasqualeMusella  
PNGpng met.png r2 r1 manage 29.4 K 2008-10-02 - 18:28 PasqualeMusella  
PNGpng met_distribs.png r1 manage 32.4 K 2008-10-02 - 17:18 PasqualeMusella  
PNGpng muGammaDeltaR_distribs.png r2 r1 manage 22.5 K 2008-10-16 - 19:45 PasqualeMusella  
PNGpng muPt_distribs.png r1 manage 19.7 K 2008-10-16 - 19:45 PasqualeMusella  
PNGpng muSel.png r3 r2 r1 manage 18.6 K 2008-10-16 - 19:38 PasqualeMusella  
PNGpng muVeto.png r2 r1 manage 19.9 K 2008-10-16 - 19:43 PasqualeMusella  
PNGpng nZVetoMu_distribs.png r2 r1 manage 14.3 K 2008-10-16 - 19:46 PasqualeMusella  
PNGpng photonId.png r3 r2 r1 manage 23.4 K 2008-10-16 - 19:50 PasqualeMusella  
PNGpng wMt_distribs.png r2 r1 manage 21.8 K 2008-10-16 - 19:47 PasqualeMusella  
PNGpng wVetoCut.png r2 r1 manage 29.1 K 2008-10-02 - 18:30 PasqualeMusella  
PNGpng zToMuMusMass_distribs.png r2 r1 manage 20.6 K 2008-10-16 - 19:47 PasqualeMusella  
PNGpng zVeto.png r3 r2 r1 manage 19.8 K 2008-10-16 - 19:44 PasqualeMusella  
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Topic revision: r18 - 2008-10-23 - PasqualeMusella
 
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