Colour coherence of soft gluons in the fully unintegrated NLO singlet kernels

TL;DR

This paper analyzes the role of colour coherence in the cancellation of infra-red singularities in next-to-leading-order gluon-quark kernels, providing both numerical and analytical insights into unintegrated distributions.

Contribution

It introduces a detailed analysis of colour coherence effects in NLO singlet kernels, highlighting their importance for infra-red singularity cancellations.

Findings

Colour coherence is crucial for infra-red singularity cancellations.

Numerical analysis confirms the significance of coherence effects.

Analytical formulae support the numerical results.

Abstract

Feynman diagrams with two real partons contributing to the next-to-leading-order singlet gluon-quark DGLAP kernel are analysed. The infra-red singularities of unintegrated distributions are examined numerically. The analytical formulae are also given in some cases. The role of the colour coherence effects is found to be crucial for cancellations of the double- and single-logarithmic infra-red singularities.