A measurement of the top-antitop production charge asymmetry A(C) is presented using data corresponding to an integrated luminosity of 1.04 fb(-1) of pp collisions at root s = 7 TeV collected by the ATLAS detector at the LHC. Events are selected with a single lepton (electron or muon), missing transverse momentum and at least four jets of which at least one jet is identified as coming from a b-quark. A kinematic fit is used to reconstruct the t (t) over bar event topology. After background subtraction, a Bayesian unfolding procedure is performed to correct for acceptance and detector effects. The measured value of A(C) is A(C) =-0.019+/-0.028 (stat.)+/-0.024 (syst.), consistent with the prediction from the MC@NLO Monte Carlo generator of A(C) = 0.006+/-0.002. Measurements of AC in two ranges of invariant mass of the top-antitop pair are also shown.
Aad, G., Abbott, B., Abdallah, J., Abdelalim, A.a., Abdesselam, A., Abdinov, O., et al. (2012). Measurement of the charge asymmetry in top quark pair production in pp collisions at root s=7 TeV using the ATLAS detector. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS, 72(6), 1-27 [10.1140/epjc/s10052-012-2039-5].