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Measurement of Wγ and Zγ production in pp collisions at sqrt(s) = 7 TeV

A measurement of Wγ and Zγ production in proton–proton collisions at sqrt(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 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 Zγ 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 WWγ, ZZγ, and Zγγ trilinear gauge couplings at are set.

CERN; CMS; LHC

The CMS Collaboration