Two-loop splitting amplitudes and the single-real contribution to inclusive Higgs production at N3LO

TL;DR

This paper calculates two-loop splitting amplitudes in QCD and uses them to derive the single-real contribution to inclusive Higgs production at N3LO, advancing precision in theoretical predictions.

Contribution

It provides the first complete computation of two-loop splitting amplitudes for all simple collinear processes, including subleading terms, and applies these results to Higgs production at N3LO.

Findings

Derived analytical expression for two-loop single-real Higgs production contribution.

Computed two-loop splitting amplitudes for all simple collinear processes.

Enhanced theoretical precision for Higgs production cross-section at N3LO.

Abstract

The factorisation of QCD matrix elements in the limit of two external partons becoming collinear is described by process-independent splitting amplitudes, which can be expanded systematically in perturbation theory. Working in conventional dimensional regularisation, we compute the two-loop splitting amplitudes for all simple collinear splitting processes, including subleading terms in the regularisation parameter. Our results are then applied to derive an analytical expression for the two-loop single-real contribution to inclusive Higgs boson production in gluon fusion to fourth order (N3LO) in perturbative QCD.