Measurement of the combined WW and WZ production cross section in the semileptonic final state in proton-proton collisions at √s = 7 TeV with the ATLAS detector

A study of WW/WZ production in the semileptonic final state using a 4.7 ± 0.2 fb−1 sample of proton-proton collisions at √s = 7 TeV recorded with the ATLAS detector at the Large Hadron Collider in 2011 is presented. The cross section is measured in the WW/WZ → ℓνq¯q′ decay channel where the lepton can be a muon or an electron. The measured cross section is σ(WW + WZ) = 72 ± 9 (stat.) ± 15 (syst.) ± 13 (MC stat.) pb, consistent with the Standard Model expectation of 63.4 ± 2.6 pb.