SMEFT chromomagnetic dipole operator contributions to $t{\bar t}$ production at approximate NNLO in QCD

TL;DR

This paper calculates higher-order QCD corrections to top-antitop production at the LHC within the Standard Model Effective Field Theory, focusing on the chromomagnetic dipole operator's effects on total and differential cross sections.

Contribution

It provides approximate NNLO QCD corrections for new physics effects from the top-quark chromomagnetic dipole operator, enhancing precision in top-quark pair production predictions.

Findings

New physics contributions to total cross section at approximate NNLO

Differential distributions in top-quark transverse momentum computed at approximate NNLO

Uncertainty estimates from scale dependence and parton distribution functions included

Abstract

We study higher-order QCD corrections for the production of a top-antitop quark pair ($t{\bar t}$ production) at the Large Hadron Collider in the Standard Model Effective Field Theory. We consider effects of new physics parametrized by the top-quark chromomagnetic dipole operator. We calculate new physics contributions to the total cross section at approximate NNLO, with second-order soft-gluon corrections added to the complete NLO result, including uncertainties from scale dependence and from parton distributions. We also calculate new physics contributions at approximate NNLO for differential distributions in top-quark transverse momentum.