Measurement of W ± Z production in proton-proton collisions at √s=7~TeV with the ATLAS detector

A study of W ± Z production in proton-proton collisions at √ 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 σ tot W Z = 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.