Measurement of the forward-backward asymmetry in top-antitop quark production in proton-antiproton collisions

TL;DR

This paper reports a new measurement of the forward-backward asymmetry in top-antitop quark production in proton-antiproton collisions, comparing experimental results with Standard Model predictions and exploring related kinematic correlations.

Contribution

It introduces a novel measurement of the asymmetry using two observables and provides unfolded results for better comparison with theoretical models.

Findings

Measured asymmetry of 19.6% with uncertainty

Compared results to MC@NLO predictions showing discrepancy

Analyzed correlation between asymmetry and ttbar transverse momentum

Abstract

We present a new measurement of the forward-backward asymmetry in ttbar production in ppbar collisions in the lepton+jets channel at D0. We measure asymmetries from two different observables and unfold the data to allow the results to be compared to standard model predictions. For the unfolded asymmetry based on the Delta-y variable, we measure (19.6 +/- 6.5)%, compared with an MC@NLO-based prediction of (5.0 +/- 0.1)%. We also discuss the correlation between the asymmetry and the transverse momentum of the ttbar system.