Measurements of the charge asymmetry in top-quark pair production in the dilepton final state at √s = 8 TeV with the ATLAS detector

Aad, G; Abbott, B; Abdallah, J; Abdinov, O; Abeloos, B; Aben, R; Abolins, M; AbouZeid, O S; Abraham, N L; Abramowicz, H; Abreu, H; Abreu, R; Abulaiti, Y; Acharya, B S; Adamczyk, L; Adams, D L; Adelman, J; Adomeit, S; Adye, T; Affolder, A A; Agatonovic-Jovin, T; Agricola, J; Aguilar-Saavedra, J A; Ahlen, S P; Ahmadov, F; Aielli, G; Akerstedt, H; Åkesson, T P A; Akimov, A V; Alberghi, G L; Albert, J; Albrand, S

Measurements of the charge asymmetry in top-quark pair production in the dilepton final state at √s = 8 TeV with the ATLAS detector

Journal Article

2016

Journal Title

Physical Review D - Particles, Fields, Gravitation, and Cosmology

Link to Journal

https://dx.doi.org/10.1103/PhysRevD.94.032006

Department

Department of Physics

Faculty

Faculty of Science

Abstract

Measurements of the top--antitop quark pair production charge asymmetry in the dilepton channel are presented using data corresponding to an integrated luminosity of $20.3$ $textrm{fb}{-1}$ from $pp$ collisions at a center-of-mass energy of $sqrt{s} = 8$ 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 $tbar{t}$ system are performed both in the full phase space and in a fiducial phase space closely matching the detector acceptance. Two observables are studied: $A{ellell}_{textrm{C}}$ based on the selected leptons and $A{tbar{t}}_{textrm{C}}$ based on the reconstructed $tbar{t}$ final state. The inclusive asymmetries are measured in the full phase space to be $A{ellell}_{textrm{C}} = 0.008 pm 0.006$ and $A{tbar{t}}_{textrm{C}} = 0.021 pm 0.016$, which are in agreement with the Standard Model predictions of $A{ellell}_{textrm{C}} = 0.0064 pm 0.0003 $ and $A{tbar{t}}_{textrm{C}} = 0.0111 pm 0.0004$.