arXiv:1010.4478·v2·High Energy Physics — Phenomenology
The quark and gluon form factors to three loops in QCD through to O(eps^2)
T. Gehrmann · (Zurich U.) · E.W.N. Glover · (Durham U., IPPP) · T. Huber · (Siegen U.) · N. Ikizlerli · (Durham U., IPPP) · C. Studerus · (Zurich U. & Bielefeld U.)
Abstract
We give explicit formulae for the O(eps) and O(eps^2) contributions to the unrenormalised three loop QCD corrections to quark and gluon form factors. These contributions have at most transcendentality weight eight. The O(eps) terms of the three-loop form factors are required for the extraction of the four-loop quark and gluon collinear anomalous dimensions. The O(eps^2) terms represent an irreducible contribution to the finite part of the form factors at four-loops. For the sake of completeness, we also give the contributions to the one and two loop form factors to the same transcendentality weight eight.
Comments: 12 pages, 1 figure. The expressions for the form factors are attached in electronic form to the source of the present submission. v2: minor modifications, matches published version. arXiv admin note: text overlap with arXiv:1004.3653