Zgamma production and limits on anomalous ZZgamma and Zgammagamma couplings in ppbar collisions at sqrt(s)=1.96 TeV

TL;DR

This paper reports a measurement of Zgamma production in proton-antiproton collisions, confirming Standard Model predictions and setting limits on possible anomalous couplings using photon transverse momentum data.

Contribution

First measurement of Zgamma production at Tevatron combining electron and muon channels, with limits on anomalous couplings from photon p_T spectrum.

Findings

Measured total and differential cross sections consistent with Standard Model

Set limits on anomalous ZZgamma and Zgammagamma couplings

Used photon transverse momentum spectrum for coupling constraints

Abstract

We present a measurement of ppbar->Zgamma->ll+gamma (l = e, mu) production with a data sample corresponding to an integrated luminosity of 6.2 fb^{-1} collected by the D0 detector at the Fermilab Tevatron ppbar Collider. The results of the electron and muon channels are combined, and we measure the total production cross section and the differential cross section dsigma/dp_T^gamma, where p_T^gamma is the momentum of the photon in the plane transverse to the beamline. The results obtained are consistent with the standard model predictions from next-to-leading order calculations. We use the transverse momentum spectrum of the photon to place limits on anomalous ZZgamma and Zgammagamma couplings.