Top-quark pair production at next-to-next-to-leading order QCD in electron positron collisions

TL;DR

This paper develops a formalism within the antenna subtraction framework to compute top-quark pair production at NNLO in QCD for electron-positron collisions, enabling precise differential predictions including the forward-backward asymmetry.

Contribution

It introduces a new formalism for NNLO QCD calculations of massive quark pair production in electron-positron collisions, applicable to any infrared-safe observable.

Findings

Computed top-quark pair production cross section and distributions.

Determined the top-quark forward-backward asymmetry at order α_s^2.

Results agree with previous computations of the asymmetry.

Abstract

We set up a formalism, within the antenna subtraction framework, for computing the production of a massive quark-antiquark pair in electron positron collisions at next-to-next-to-leading order in the coupling $\alpha_s$ of quantum chromodynamics at the differential level. Our formalism applies to the calculation of any infrared-safe observable. We apply this set-up to the production of top-quark top antiquark pairs in the continuum. We compute the production cross section and several distributions. We determine, in particular, the top-quark forward-backward asymmetry at order $\alpha_s^2$. Our result agrees with previous computations of this observable.