On quartic colour factors in splitting functions and the gluon cusp anomalous dimension
Abstract
We have computed the contributions of the quartic Casimir invariants to the four-loop anomalous dimensions of twist-2 spin-N operators at N =< 16. The results provide new information on the structure of the next-to-next-to-next-to-leading order (N^3LO) splitting functions P_{ik}^(3)(x) for the evolution of parton distributions, and facilitate approximate expressions which include the quartic-Casimir contributions to the (light-like) gluon cusp anomalous dimension. These quantities turn out to be closely related, by a generalization of the lower-order `Casimir scaling', to the corresponding quark results. Using these findings, we present an approximate result for the four-loop gluon cusp anomalous dimension in QCD which is sufficient for phenomenological applications.
Keywords
Cite
@article{arxiv.1805.09638,
title = {On quartic colour factors in splitting functions and the gluon cusp anomalous dimension},
author = {S. Moch and B. Ruijl and T. Ueda and J. A. M. Vermaseren and A. Vogt},
journal= {arXiv preprint arXiv:1805.09638},
year = {2018}
}
Comments
12 pages, LaTeX