W+gamma and Z+gamma production blessed results for Winter 2004 |
Event criteria for W+gamma |
|
Electron |
Et (transverse energy) > 25GeV, |eta(electron)|<1.1 |
Muon |
Pt (transverse momentum) > 20GeV, |eta(muon)|<1.1 |
Neutrino | MEt (missing transverse energy)
> 25 GeV (electron analysis), 20 GeV (muon analysis) |
Transverse mass(electron,
neutrino) |
30 < Mt < 120 GeV |
Photon |
Et(transverse energy) > 7
GeV,� |eta(photon)|<1.1 |
Wgamma events yields |
Central : Luminosity 202 [pb-1] ����������� (stat.)�(sys.) |
signal MC | 180.51 � 2.08 � 10.11 |
W+jet Backgound |
49.52 � 0.10 � 14.95 |
Zgamma |
22.37 � 0.38 � 1.20 |
Wgamma-> tau nu gamma |
3.23 � 0.24 � 0.17 |
total SM+BG |
255.63 � 2.13 � 26.43 |
Data |
259 |
Cross section for Et(gamma)>7 GeV and DeltaR(lepton,gamma)>0.7:
|
|
sigma(Wgamma)
x BR(W->lepton +
nu) |
19.7 � 1.7 (stat.) � 2.0(sys.) � 1.1 (lum.) |
Theory : sigma(Wgamma) x BR(W-> lepton + nu)� |
19.3 � 1.4 (sys.) [pb] |
Event criteria for Z+gamma |
|
Electron |
Et (transverse energy) >
25GeV, |eta(electron)|<2.8 central EM calorimeter (CEM) covers |eta|< 1.1 and plug calorimeter covers 1.2 < |eta|<2.8 |
Muon |
Pt (transverse energy) >
20GeV, |eta(muon)|<1.1 |
Invariant mass(lepton,lepton)
|
M > 40 GeV |
Photon |
Et(transverse energy) > 7
GeV,� |eta(photon)|<1.1 |
Zgamma events yields |
Central : Luminosity 202 [pb-1] ����������� (stat.)�(sys.) |
signal MC | 65.76 � 3.76 |
Z+jet Backgound |
4.44 � 1.33 |
other BG |
0.26 � 0.20 |
total SM+BG |
70.46 � 4.00 |
Data |
69 |
Cross section for Et(gamma)>7 GeV and DeltaR(lepton,gamma)>0.7
|
|
sigma(Zgamma) x BR(Z->lepton + lepton) |
5.3 � 0.6 (stat.) � 0.3(sys.) � 0.3 (lum.) |
Theory : sigma(Zgamma) x BR(Z-> lepton + lepton)� |
5.4 � 0.3 (sys.) [pb] |
Kinematic Distributions | Wgamma |
Zgamma |
Et(gamma) | ![]() |
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Et(gamma) on log scale | ![]() |
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Delta R(lepton, photon) | ![]() |
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Wgamma: Transverse mass (lepton, neutrino) Zgamma: Di-lepton invariant mass |
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Wgamma: Cluster transverse mass(lepton, photon, neutrino) Zgamma: 3-body-mass(lepton, lepton, neutrino) |
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Wgamma: Cluster transverse mass vs�transverse mass Zgamma: 3-body vs dilepton mass |
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Charge signed rapidity difference |