Inclusive and differential measurements of the t t-bar charge asymmetry in proton-proton collisions at sqrt(s) = 7 TeV

TL;DR

This paper reports measurements of the top-antitop quark charge asymmetry in proton-proton collisions at 7 TeV, using CMS data, finding results consistent with the Standard Model predictions and no significant asymmetry.

Contribution

First to perform inclusive and differential measurements of the t t-bar charge asymmetry at 7 TeV with CMS data, including rapidity, transverse momentum, and invariant mass dependencies.

Findings

Measured inclusive asymmetry A(C) = 0.004 +/- 0.015

Results are consistent with zero asymmetry

Findings agree with Standard Model predictions

Abstract

The t t-bar charge asymmetry is measured in events containing a charged lepton (electron or muon) and at least four jets, one of which is identified as originating from b-quark hadronization. The analyzed dataset corresponds to an integrated luminosity of 5.0 inverse femtobarns collected with the CMS detector at the LHC. An inclusive and three differential measurements of the t t-bar charge asymmetry as a function of rapidity, transverse momentum, and invariant mass of the t t-bar system are presented. The measured inclusive t t-bar charge asymmetry is A(C) = 0.004 +/- 0.010 (stat.) +/- 0.011 (syst.). This result and the three differential measurements are consistent with zero asymmetry as well as with the predictions of the standard model.