Progress in top-quark pair production cross section calculations and impact on parton distribution functions of the proton

TL;DR

This paper reviews recent advances in calculating top-quark pair production cross sections at the LHC, highlighting the impact of higher-order QCD and electroweak corrections on proton PDFs and comparing theoretical predictions with experimental data.

Contribution

It presents the latest progress in top-quark pair production calculations, including approximate N$^3$LO QCD and NLO EW corrections, and analyzes their effects on parton distribution functions.

Findings

Higher-order corrections improve agreement with experimental data.

Gluon PDF at large x is significantly affected by new measurements.

Optimal data selection enhances global PDF fits.

Abstract

We discuss the impact of eligible top-quark pair production differential cross-section measurements at the LHC with a collision energy of 13 TeV on the parton distribution functions (PDFs) of the proton as well as the impact of approximate next-to-next-to-next-to-leading order (aN$^3$LO) QCD corrections combined with next-to-leading order (NLO) electroweak (EW) corrections on $t\bar t$ observables. We illustrate the effects on the gluon PDF at large $x$ from an optimal baseline selection of data in NNLO global fits, and show comparisons between the theory prediction for $t\bar t$ total and differential cross sections at aN$^3$LO QCD combined with NLO EW and recent measurements from the ATLAS and CMS collaborations at the LHC.