Measurement of the cross section for top-quark pair production in pp collisions at √s = 7 TeV with the ATLAS detector using final states with two high-pT leptons

Abstract

A measurement is reported of the production cross section of top-quark pairs (t¯t) in proton-proton collisions at a center-of-mass energy of 7 TeV recorded with the ATLAS detector at the LHC. Candidate events have a signature consistent with containing two isolated leptons, large missing transverse momentum, and at least two jets. Using a data sample corresponding to an integrated luminosity of 0.70 fb−1, a t¯t production cross section t¯t = 176 ± 5(stat.)+14 −11(syst.) ± 8(lum.) pb is measured for an assumed top-quark mass of mt = 172.5 GeV. This measurement is in good agreement with Standard Model predictions.