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 ppˉ and ttˉ rest frames as a function of the rapidity and invariant mass of the ttˉ 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.
@article{arxiv.1106.6051,
title = {The top-pair forward-backward asymmetry beyond NLO},
author = {Valentin Ahrens and Andrea Ferroglia and Matthias Neubert and Ben D. Pecjak and Li Lin Yang},
journal= {arXiv preprint arXiv:1106.6051},
year = {2013}
}