NNLO corrections to top pair production at hadron colliders: the quark-gluon reaction

TL;DR

This paper calculates the NNLO QCD corrections to top pair production via quark-gluon reactions at hadron colliders, providing more precise cross-section predictions and analyzing the accuracy of high-energy approximations.

Contribution

It presents the first NNLO calculation for the qg initiated top pair production process, improving theoretical precision and assessing approximation methods.

Findings

Moderate (~1%) correction to cross-sections at Tevatron and LHC.

Reduced scale uncertainty at LHC, unchanged at Tevatron.

High-energy approximation deviates significantly from exact results.

Abstract

We compute the next-to-next-to-leading order QCD correction to the total inclusive top pair production cross-section in the reaction qg \to t\bar t + X. We find moderate O(1%) correction to central values at both Tevatron and LHC. The scale variation of the cross-section remains unchanged at the Tevatron and is significantly reduced at the LHC. We find that recently introduced approximation based on the high-energy limit of the top pair cross-section significantly deviates from the exact result. The results derived in the present work are included in version 1.4 of the program Top++. Work towards computing the reaction gg\to t\bar t+X is ongoing.