English

Towards Colour Flow Evolution at Two Loops

High Energy Physics - Phenomenology 2021-06-16 v1

Abstract

We calculate the two-loop and one-loop/one-emission contributions required for soft gluon evolution at the next-to-leading order. The colour structures are expressed in the colour flow basis, and the kinematic dependence and loop integrals are expressed in terms of multiple cuts and phase-space-like integrals. This directly allows to use them in the resummation of non-global observables and improved parton shower algorithms beyond the leading order and beyond the leading colour limit. Within the colour flow basis it becomes apparent that correlations beyond a dipole picture emerge even in colour-diagonal elements of the virtual corrections.

Keywords

Cite

@article{arxiv.2012.15215,
  title  = {Towards Colour Flow Evolution at Two Loops},
  author = {Simon Plätzer and Ines Ruffa},
  journal= {arXiv preprint arXiv:2012.15215},
  year   = {2021}
}

Comments

38 pages, 2 tables, 2 figures and several diagrams, detailed appendices

R2 v1 2026-06-23T21:36:18.768Z