QCD splitting functions beyond kinematical limits

TL;DR

This paper systematically decomposes QCD splitting functions into scalar dipole radiators and remainders, revealing universal features and extending understanding beyond traditional kinematical limits.

Contribution

It introduces a novel decomposition of QCD splitting functions into scalar components and remainders, applicable beyond kinematic approximations.

Findings

Derived multipole radiator functions resemble known soft gluon currents.

Components include sub-leading terms with universal properties.

Framework applicable up to second order in strong coupling.

Abstract

We present a systematic decomposition of QCD splitting functions into scalar dipole radiators and pure splitting remainders up to second order in the strong coupling. The individual components contain terms that are formally sub-leading in soft or collinear scaling parameters, but well understood and universal due to their origin in scalar QCD. The multipole radiator functions which we derive share essential features of the known double-soft and one-loop soft gluon currents, and are not based on kinematical approximations.