Measurement of the charge asymmetry in top-quark pair production in the lepton-plus-jets final state in pp collision data at √ s = 8 TeV with the ATLAS detector

This paper reports inclusive and differential measurements of the t ¯ t charge asymmetry A C in 20 . 3 fb − 1 of √ s = 8 TeV pp collisions recorded by the ATLAS experiment at the Large Hadron Collider at CERN. Three differential measurements areperformedas afunctionof theinvariant mass, transverse momentum and longitudinal boost of the t ¯ t system. The t ¯ t pairs are selected in the single-lepton channels ( e or μ ) with at least four jets, and a likelihood fit is used to reconstruct the t ¯ t event kinematics. A Bayesian unfolding procedure is performed to infer the asymmetry at parton level from the observed data distribution. The inclusive t ¯ t charge asymmetry is measured to be A C = 0 . 009 ± 0 . 005 (stat. + syst.). The inclusive and differential measurements are compatible with the values predicted by the Standard Model.

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