Measurement of WZ production in proton-proton collisions at sqrt(s) = 7 TeV with the ATLAS detector

TL;DR

This paper measures the WZ production cross-section in proton-proton collisions at 7 TeV using ATLAS data, confirming consistency with the Standard Model and setting limits on anomalous gauge couplings.

Contribution

First measurement of WZ production cross-section at 7 TeV with detailed analysis and limits on anomalous couplings using ATLAS data.

Findings

Measured total cross-section: 19.0 pb with uncertainties.

Observed 317 WZ candidate events with background estimate of 68 events.

Set limits on anomalous triple gauge boson couplings.

Abstract

A study of WZ production in proton-proton collisions at sqrt(s) = 7 TeV is presented using data corresponding to an integrated luminosity of 4.6 fb^-1 collected with the ATLAS detector at the Large Hadron Collider in 2011. In total, 317 candidates, with a background expectation of 68+/-10 events, are observed in double-leptonic decay final states with electrons, muons and missing transverse momentum. The total cross-section is determined to be sigma_WZ(tot) = 19.0+1.4/-1.3(stat.)+/-0.9(syst.)+/-0.4(lumi.) pb, consistent with the Standard Model expectation of 17.6+1.1/-1.0 pb. Limits on anomalous triple gauge boson couplings are derived using the transverse momentum spectrum of Z bosons in the selected events. The cross section is also presented as a function of Z boson transverse momentum and diboson invariant mass.