Two-loop QCD corrections to massless identical quark scattering

TL;DR

The paper addresses the precision needed for NNLO predictions of jet production by computing the two-loop QCD corrections to massless identical-quark scattering, specifically q qbar -> q qbar and related channels, within conventional dimensional regularization and the MSbar scheme. It isolates the infrared pole structure in agreement with Catani and provides the finite remainders for the mixed channels in terms of polylogarithms, organized by color factors. The results include a detailed decomposition of the two-loop interference term into pole and finite parts, with explicit channel-specific coefficients and cross-checks against QED limits. This work constitutes a crucial component for achieving fully analytic and numerical NNLO jet cross sections in hadron-hadron collisions, enabling more accurate predictions for collider phenomenology.

Abstract

We present the two-loop virtual QCD corrections to the scattering of massless identical quarks, q qbar to q qbar, in conventional dimensional regularisation and using the MSbar scheme. The structure of the infrared divergences agrees with that predicted by Catani while expressions for the finite remainder are given for the q qbar to qbar q and the q q to q q (qbar qbar to qbar qbar) scattering processes in terms of polylogarithms. The results presented here form a vital part of the next-to-next-to-leading order contribution to inclusive jet production in hadron colliders and will play a crucial role in improving the theoretical prediction for jet cross sections in hadron-hadron collisions.