Measurements of Wgamma and Zgamma production in pp collisions at sqrt{s}= 7 TeV with the ATLAS detector at the LHC

TL;DR

This paper reports measurements of Wgamma and Zgamma production cross sections in proton-proton collisions at 7 TeV using the ATLAS detector, testing the Standard Model and searching for new physics phenomena.

Contribution

First measurements of Wgamma and Zgamma production cross sections at 7 TeV with the ATLAS detector, constraining anomalous gauge couplings and vector resonance production.

Findings

No deviations from Standard Model predictions observed.

Limits set on anomalous triple-gauge-boson couplings.

Constraints on production of new vector meson resonances.

Abstract

The integrated and differential fiducial cross sections for the production of a W or Z boson in association with a high-energy photon are measured using pp collisions at sqrt{s} = 7 TeV. The analyses use a data sample with an integrated luminosity of 4.6 fb^{-1} collected by the ATLAS detector during the 2011 LHC data-taking period. Events are selected using leptonic decays of the W and Z bosons (W(e nu,mu nu) and Z(e+ e-, mu+ mu-, nu nubar)) with the requirement of an associated isolated photon. The data are used to test the electroweak sector of the Standard Model and search for evidence for new phenomena. The measurements are used to probe the anomalous WWgamma, ZZgamma and Zgammagamma triple-gauge-boson couplings and to search for the production of vector resonances decaying to Zgamma and Wgamma. No deviations from Standard Model predictions are observed and limits are placed on anomalous triple-gauge-boson couplings and on the production of new vector meson resonances.