Measurement of the W gamma and Z gamma inclusive cross sections in pp collisions at sqrt(s) = 7 TeV and limits on anomalous triple gauge boson couplings

TL;DR

This paper measures W gamma and Z gamma production cross sections at 7 TeV and sets limits on anomalous gauge couplings using CMS data, finding results consistent with the Standard Model.

Contribution

It provides the first measurement of these cross sections at 7 TeV and establishes new limits on anomalous triple gauge couplings.

Findings

Cross sections measured for photon pT > 15 GeV

No deviations from Standard Model predictions

Limits set on anomalous gauge couplings

Abstract

Measurements of W gamma and Z gamma production in proton-proton collisions at sqrt(s) = 7 TeV are used to extract limits on anomalous triple gauge couplings. The results are based on data recorded by the CMS experiment at the LHC that correspond to an integrated luminosity of 5.0 inverse femtobarns. The cross sections are measured for photon transverse momenta pt[gamma] > 15 GeV, and for separations between photons and final-state charged leptons in the pseudorapidity-azimuthal plane of Delta R[l, gamma] > 0.7 in l nu gamma and ll gamma final states, where l refers either to an electron or a muon. A dilepton invariant mass requirement of m[ll] > 50 GeV is imposed for the Z gamma process. No deviations are observed relative to predictions from the standard model, and limits are set on anomalous WW gamma, ZZ gamma, and Z gamma gamma triple gauge couplings.