Running couplings for the simultaneous decoupling of heavy quarks
Abstract
Scale-invariant running couplings are constructed for several quarks being decoupled together, without reference to intermediate thresholds. Large-momentum scales can also be included. The result is a multi-scale generalization of the renormalization group applicable to any order. Inconsistencies in the usual decoupling procedure with a single running coupling can then be avoided, e.g. when cancelling anomalous corrections from t,b quarks to the axial charge of the proton.
Cite
@article{arxiv.hep-ph/0507278,
title = {Running couplings for the simultaneous decoupling of heavy quarks},
author = {Steven D. Bass and R. J. Crewther and F. M. Steffens and A. W. Thomas},
journal= {arXiv preprint arXiv:hep-ph/0507278},
year = {2010}
}
Comments
12 pages, 1 figure, version to appear in PLB. Pages 8-11 and Fig. 1 are new, with consequent changes to the abstract, page 2, and the references. We show that our multi-scale renormalization group is needed to achieve anomaly cancellation in t,b decoupling from the weak neutral current, and extend it to include large momenta