The top-pair forward-backward asymmetry beyond NLO

TL;DR

This paper enhances theoretical predictions of the top-quark pair production forward-backward asymmetry at the Tevatron by incorporating higher-order corrections and soft gluon resummation, providing more accurate and detailed results for comparison with experimental data.

Contribution

It introduces improved predictions for the asymmetry using NNLL resummation in two kinematic schemes, extending previous NLO calculations and providing detailed binned results for experimental comparison.

Findings

Enhanced asymmetry predictions with NNLL resummation

Provided detailed binned results for large invariant mass and rapidity difference

Calculated top-quark charge asymmetry at the LHC with rapidity cuts

Abstract

We make use of recent results in effective theory and higher-order perturbative calculations to improve the theoretical predictions of the QCD contribution to the top-quark pair production forward-backward asymmetry at the Tevatron. In particular, we supplement the fixed-order NLO calculation with higher-order corrections from soft gluon resummation at NNLL accuracy performed in two different kinematic schemes, which allows us to make improved predictions for the asymmetry in the $p\bar p$ and $t\bar t$ rest frames as a function of the rapidity and invariant mass of the $t\bar t$ pair. Furthermore, we provide binned results which can be compared with the recent measurements of the forward-backward asymmetry in events with a large pair invariant mass or rapidity difference. Finally, we calculate at NLO+NNLL order the top-quark charge asymmetry at the LHC as a function of a lower rapidity cut-off for the top and antitop quarks.