On Rapidity Divergences in the Soft and Collinear Limits of QCD
High Energy Physics - Phenomenology
2015-06-17 v1
Abstract
We consider the definition of a transverse-momentum-dependent parton distribution function (TMDPDF) and its evolution properties given a factorization theorem of Drell- Yan lepton pair production with a non-vanishing transverse momentum. We discuss rapidity divergences that exist in both limits of QCD: the soft and collinear. We argue that only when a specific combination of the soft and collinear matrix elements is formed, rapidity divergences cancel. We also argue that the soft matrix element, calculated in perturbation theory, contains only rapidity divergences and there is no genuine long-distance infra-red divergences.
Keywords
Cite
@article{arxiv.1310.8541,
title = {On Rapidity Divergences in the Soft and Collinear Limits of QCD},
author = {Miguel G. Echevarria and Ahmad Idilbi and Ignazio Scimemi},
journal= {arXiv preprint arXiv:1310.8541},
year = {2015}
}
Comments
11 pages, 5 figures. To appear in proceedings of QCD Evolution workshop 2013