Double-real corrections at O(alpha alpha_s) to single gauge boson production

TL;DR

This paper computes the O(alpha alpha_s) corrections to single gauge boson production at hadron colliders, focusing on real emission subprocesses, using advanced integral reduction techniques to evaluate complex master integrals.

Contribution

It introduces the calculation of 14 new master integrals involving massive lines, expanding the theoretical tools for higher-order corrections in gauge boson production.

Findings

Total cross sections expressed as Laurent series in dimensional regularization

Evaluation of 14 new master integrals with massive internal lines

Application of reverse unitarity and differential equations for integral reduction

Abstract

We consider the O(alpha alpha_s) corrections to single on-shell gauge boson production at hadron colliders. We concentrate on the contribution of all the subprocesses where the gauge boson is accompanied by the emission of two additional real partons and we evaluate the corresponding total cross sections. The latter are divergent quantities, because of soft and collinear emissions, and are expressed as Laurent series in the dimensional regularization parameter. The total cross sections are evaluated by means of reverse unitarity, i.e. expressing the phase-space integrals in terms of two-loop forward box integrals with cuts on the final state particles. The results are reduced to a combination of Master Integrals, which eventually are evaluated in terms of Generalized Polylogarithms. The presence of internal massive lines in the Feynman diagrams, due to the exchange of electroweak gauge bosons, causes the appearance of 14 Master Integrals which were not previously known in the literature and have been evaluated via Differential Equations.