Treatment of heavy quarks in QCD
Abstract
We show that to correctly describe the effects of the heavy-quark mass, m_h, in DGLAP evolution, it is necessary to work in the so-called `physical' scheme. In this way, we automatically obtain a smooth transition through the heavy-quark thresholds. Moreover, we show that to obtain NLO accuracy, it is sufficient to account for the heavy-quark mass, m_h, just in the LO (one-loop) splitting function. The use of the MS-bar factorisation scheme is not appropriate, since at NLO we deal with a mixture of quarks and gluon (that is, the mass of the heavy parton is not well-defined). The formulae for the explicit m_h dependence of the splitting functions, and for alpha_s, are presented.
Keywords
Cite
@article{arxiv.1307.3508,
title = {Treatment of heavy quarks in QCD},
author = {E. G. de Oliveira and A. D. Martin and M. G. Ryskin and A. G. Shuvaev},
journal= {arXiv preprint arXiv:1307.3508},
year = {2015}
}
Comments
14 pages, 3 figures, references updated, version to be published in EPJC