Top-quark production cross sections at higher perturbative orders

TL;DR

This paper calculates higher-order QCD and electroweak corrections to various top-quark production processes, demonstrating the dominance of soft-gluon effects and providing improved theoretical cross-section predictions compared to LHC data.

Contribution

It introduces approximate NNLO and N$^3$LO calculations with soft-gluon corrections for multiple top-quark production processes, enhancing precision over previous results.

Findings

Soft-gluon corrections are numerically dominant in all processes.

Approximate higher-order cross sections align well with LHC measurements.

Electroweak corrections are included for specific processes.

Abstract

I present calculations of higher-order corrections to top-quark production via three different processes: the production of a top-antitop pair and a $Z$ boson; single-top quark production in the $s$-channel; and top-antitop production with a Higgs boson. It is shown that the contributions from soft-gluon corrections are numerically dominant and large in all these processes. I present approximate NNLO (aNNLO) and approximate N$^3$LO (aN$^3$LO) cross sections that include soft-gluon corrections added to the exact NLO QCD results. Electroweak corrections through NLO are also included for $t{\bar t}Z$ and $t{\bar t}H$ production. The theoretical predictions are compared to LHC measurements of total cross sections for these processes.