Measurement of the top quark pair production charge asymmetry in proton-proton collisions at √s = 7 TeV in ATLAS experiment

Measurement of top quark pair production charge asymmetry serves as an important test of Standard Model of particle physics (SM). The charge asymmetry observed in recent measurements from Tevatron was greater than predictions with regard to SM. This paper presents a measurement of the top quark pair production charge asymmetry A_C using proton-proton collisions at a centre-of-mass energy √s = 7 TeV collected by the ATLAS detector at the LHC. The measured value is A_C = 0.006± 0.010, where the uncertainty includes both the statistical and the systematic components. All measurements are consistent with the SM predictions.

Top quark physics is traditionally one of the major centres of our work in ATLAS experiment. Top quark – the heaviest elementary particle – is mainly due to its mass regarded as a suitable candidate that could reveal glints of new physics beyond Standard Model. Among the main authors of the analysis in the article were two members of our group.

Comparison of A_C measurements performed in ATLAS experiment at LHC (green band) and front back asymmetry (A_FB) measurements in CDF experiment at Tevatron with Standard Model (SM) predictions and other physical models beyond the SM.

¹Fakultät für Mathematik und Physik, Albert-Ludwigs-Universität, Freiburg, Germany
²Institute of Physics, Academy of Sciences of the Czech Republic, Praha, Czech Republic