Measurement of Wgamma and Zgamma production in proton-proton collisions at sqrt(s)=7 TeV with the ATLAS Detector

Abstract

We present studies of W and Z bosons with associated high energy photons produced in pp collisions at sqrt(s)=7 TeV. The analysis uses 35 pb-1 of data collected by the ATLAS experiment in 2010. The event selection requires W and Z bosons decaying into high pT leptons (electrons or muons) and a photon with ET>15 GeV separated from the lepton(s) by a distance Delta_R(l,gamma)>0.7 in eta-phi space. A total of 95 (97) pp->e nu gamma _s16 X (pp->mu nu gamma _s16 X) and 25 (23) pp->e_s16 e- gamma _s16 X (pp->mu_s16 mu- gamma _s16 X) event candidates are selected. The kinematic distributions of the leptons and photons and the production cross sections are measured. The data are found to agree with Standard Model predictions that include next-to-leading-order O(alpha alpha_s) contributions.