Measurements of the charge asymmetry in top-quark pair production in the dilepton final state at $\sqrt{s}=8$ TeV with the ATLAS detector

Abstract

Measurements of the top--antitop quark pair production charge asymmetry in the dilepton channel, characterized by two high-${p}_{\rm{T}}$ leptons (electrons or muons), are presented using data corresponding to an integrated luminosity of 20.3 $\textrm{fb}^{-1}$ from $pp$ collisions at a center-of-mass energy $\sqrt{s} = 8$~TeV collected with the ATLAS detector at the Large Hadron Collider at CERN. Inclusive and differential measurements as a function of the invariant mass, transverse momentum, and longitudinal boost of the $t\bar{t}$ system are performed both in the full phase space and in a fiducial phase space closely matching the detector acceptance. Two observables are studied: $A_C^{\ell \ell}$ based on the selected leptons and $A_C^{t\bar{t}}$ based on the reconstructed $t\bar{t}$ final state. No significant deviation from the Standard Model expectations is observed.