Strong Coupling Constant with Flavour Thresholds at Four Loops in the MS-bar Scheme
High Energy Physics - Phenomenology
2009-10-30 v1 High Energy Physics - Experiment
Abstract
We present in analytic form the matching conditions for the strong coupling constant alpha_s^(n_f)(mu) at the flavour thresholds to three loops in the modified minimal-subtraction scheme. Taking into account the recently calculated coefficient beta_3 of the Callan-Symanzik beta function of quantum chromodynamics, we thus derive a four-loop formula for alpha_s^(n_f)(mu) together with appropriate relationships between the asymptotic scale parameters Lambda^(n_f) for different numbers of flavours n_f.
Cite
@article{arxiv.hep-ph/9706430,
title = {Strong Coupling Constant with Flavour Thresholds at Four Loops in the MS-bar Scheme},
author = {K. G. Chetyrkin and B. A. Kniehl and M. Steinhauser},
journal= {arXiv preprint arXiv:hep-ph/9706430},
year = {2009}
}
Comments
10 pages (Latex), 3 figures (Postscript)