NNLL threshold resummation for top-pair and single-top production

TL;DR

This paper applies NNLL threshold resummation in perturbative QCD to improve predictions for top-quark pair and single-top production at colliders, providing new approximate NNLO results that match experimental data well.

Contribution

It introduces new approximate NNLO calculations for top-quark production processes using NNLL resummation, enhancing the accuracy of theoretical predictions.

Findings

Approximate NNLO results closely match exact calculations.

Resummation improves agreement with LHC and Tevatron data.

Soft-gluon approximation is highly accurate at NNLO.

Abstract

I discuss threshold resummation at NNLL accuracy in the standard moment-space approach in perturbative QCD for top-pair and single-top production. For top quark pair production I present new approximate NNLO results for the total cross section and for the top quark transverse momentum and rapidity distributions at 8 TeV LHC energy. I discuss the accuracy of the soft-gluon approximation and show that the NLO and NNLO approximate results from resummation are practically indistinguishable from exact NLO and partial NNLO results. For single top production I present new approximate NNLO results for the total cross sections in all three channels at the LHC and also for the top quark transverse momentum distributions in t-channel production and in top-quark associated production with a W boson. For both ttbar and single-top production the agreement of theoretical results with LHC and Tevatron data is excellent.