Measurement of W gamma and Z gamma production in pp collisions at root s=7 TeV

Journal article

A measurement of W γ and Z γ production in proton-proton collisions at s=7 TeV is presented. Results are based on a data sample recorded by the CMS experiment at the LHC, corresponding to an integrated luminosity of 36 pb-1. The electron and muon decay channels of the W and Z are used. The total cross sections are measured for photon transverse energy ETγ>10 GeV and spatial separation from charged leptons in the plane of pseudorapidity and azimuthal angle ΔR(ℓ,γ)>0.7, and with an additional dilepton invariant mass requirement of Mℓℓ>50 GeV for the Z γ process. The following cross section times branching fraction values are found: σ(pp→Wγ+X)×B(W→ℓν)=56.3±5.0(stat.)±5.0(syst.)±2.3(lumi.) pb and σ(pp→Zγ+X)×B(Z→ℓℓ)=9.4±1.0(stat.)±0.6(syst.)±0.4(lumi.) pb. These measurements are in agreement with standard model predictions. The first limits on anomalous WW γ, ZZ γ, and Z γγ trilinear gauge couplings at s=7 TeV are set. © 2011 CERN.

Authors: Chatrchyan, S; Khachatryan, V; Sirunyan, A; Tumasyan, A; Adam, W

• Publication status: Published
• Journal: Physics Letters B
• Volume: 701
• Issue: 5
• Pages: 535-555
• Publication date: 2011-07-27
• DOI: 10.1016/j.physletb.2011.06.034
• ISSN: 0370-2693
• Language: English
• Keywords: Electroweak; Physics; CMS