Subleading effects in soft-gluon emission at one-loop in massless QCD

• DOI: 10.1007/jhep12(2023)126
• Publication Date: 2023-12-21T06:01:38Z
• Authors: Michał Czakon; Felix Eschment; Tom Schellenberger
• Keywords: Massless particle

A bstract We elucidate the structure of next-to-leading-power soft-gluon expansion arbitrary one-loop massless-QCD amplitudes. The is given in terms universal colour-, spin- and flavour-dependent operators acting on process-dependent gauge-invariant result proven using method expansion-by-regions tested numerically non-trivial processes with up to six partons. In principle, collinear-region contributions are expressed convolutions jet amplitudes two collinear However, we evaluate these exactly for processes. This achieved by deriving an expression next-to-leading power tree-level limit, which a novel as well. Compared previous studies, our analysis, besides being more general, yields simpler formulae that avoid derivatives limit.