Wgamma production and limits on anomalous WWgamma couplings in ppbar collisions

TL;DR

This paper reports measurements of Wgamma production cross sections and limits on anomalous WWgamma couplings using Tevatron data, confirming Standard Model predictions and setting the most stringent collider limits to date.

Contribution

First measurement of Wgamma production cross section and rapidity difference distributions at Tevatron, with new limits on anomalous WWgamma couplings.

Findings

Measured Wgamma cross section: 15.8 +/- 0.8 (stat.) +/- 1.2 (syst.) pb.

Results agree with Standard Model predictions.

Set the most stringent limits on anomalous WWgamma couplings.

Abstract

We measure the cross section and the difference in rapidities between photons and charged leptons for inclusive W -> lnu+gamma production in egamma and mugamma final states. Using data corresponding to an integrated luminosity of 4.2 fb-1 collected with the D0 detector at the Fermilab Tevatron Collider, the cross section multiplied by the branching fraction for the process ppbar -> Wgamma+X -> lnugamma+X, measured to be 15.8 +/- 0.8 (stat.) +/- 1.2 (syst.) pb, and the distribution of the charge-signed photon-lepton rapidity difference are found to be in agreement with the standard model. These results provide the most stringent limits on anomalous WWgamma couplings for data from hadron colliders: -0.4 < Delta kappa_gamma < 0.4 and -0.08 < lambda_gamma < 0.07 at the 95% C.L.