Top-quark forward-backward asymmetry in e+e- annihilation at NNLO in QCD

TL;DR

This paper presents a comprehensive NNLO QCD calculation of top-quark pair production in electron-positron annihilation, significantly improving the precision of forward-backward asymmetry predictions for future collider experiments.

Contribution

It provides the first fully differential NNLO QCD calculation of top-quark pair production and asymmetry in e+e- annihilation, reducing theoretical uncertainties.

Findings

Sizable NNLO corrections to top-quark forward-backward asymmetry.

Large reduction in theoretical uncertainties.

Enables precise determination of top quark electroweak couplings.

Abstract

We report on a complete calculation of electroweak production of top quark pairs in $e^+e^-$ annihilation at next-to-next-to-leading order in Quantum Chromodynamics. Our setup is fully differential and can be used to calculate any infrared-safe observable. Especially we calculated the next-to-next-to-leading order corrections to top-quark forward-backward asymmetry and found sizable effects. Our results show a large reduction of the theoretical uncertainties in predictions of the forward-backward asymmetry, and allow a precision determination of the top quark electroweak couplings at future $e^+e^-$ colliders.