Top-quark production cross sections at higher perturbative orders

TL;DR

Addresses precise predictions for top-quark production cross sections at high perturbative orders, highlighting the dominance of soft-gluon corrections. It uses soft-gluon resummation in 1PI kinematics to derive approximate NNLO ($aNNLO$) and approximate N$^3$LO ($aN^3LO$) cross sections, matched to exact NLO QCD results and including NLO EW corrections where applicable. The results for ttZ, s-channel single-top, and ttH show large enhancements over LO and reduced scale uncertainties, with good agreement to LHC measurements. These state-of-the-art predictions improve tests of the Standard Model and top-quark couplings at the LHC.

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.

Figures (2)

• Figure 1: The total cross sections (left) and top-quark rapidity distributions (right) for $t{\bar{t}}Z$ production in $pp$ collisions at LHC energies. Results are shown through aN$^3$LO QCD + NLO EW, and the inset plots display the $K$-factors relative to LO QCD.
• Figure 2: The total cross sections for $s$-channel single-top plus single-antitop production through aN$^3$LO NKs25 in $pp$ collisions at LHC energies. Also shown are data at 8 TeV ATLASCMSsch and 13 TeV ATLAS13sch LHC energies. The inset plot displays the $K$-factors relative to LO.