Measurements of charge and CP asymmetries in b-hadron decays using top-quark events collected by the ATLAS detector in pp collisions at √s = 8 TeV

Aaboud, M; Aad, G; Abbott, B; Abdallah, J; Abdinov, O; Abeloos, B; AbouZeid, O S; Abraham, N L; Abramowicz, H; Abreu, H; Abreu, R; Abulaiti, Y; Acharya, B S; Adachi, S; Adamczyk, L; Adams, D L; Adelman, J; Adomeit, S; Adye, T; Affolder, A A; Agatonovic-Jovin, T; 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; Alconada Verzini, M J

Measurements of charge and CP asymmetries in b-hadron decays using top-quark events collected by the ATLAS detector in pp collisions at √s = 8 TeV

Journal Article

2017

Journal Title

Journal of High Energy Physics

Link to Journal

https://dx.doi.org/10.1007/JHEP02(2017)071

Department

Department of Physics

Faculty

Faculty of Science

Abstract

Same- and opposite-sign charge asymmetries are measured in lepton+jets $tbar{t}$ events in which a $b$-hadron decays semileptonically to a soft muon, using data corresponding to an integrated luminosity of 20.3 fb${-1}$ from proton-proton collisions at a centre-of-mass energy of $sqrt{s}=8$ TeV collected with the ATLAS detector at the Large Hadron Collider at CERN. The charge asymmetries are based on the charge of the lepton from the top-quark decay and the charge of the soft muon from the semileptonic decay of a $b$-hadron and are measured in a fiducial region corresponding to the experimental acceptance. Four $CP$ asymmetries (one mixing and three direct) are measured and are found to be compatible with zero and consistent with the Standard Model.