Four-Loop Anomalous Dimensions for Radiative Flavour-Changing Decays
High Energy Physics - Phenomenology
2010-10-27 v1
Abstract
We evaluate the complete four-loop anomalous dimension matrix that is necessary for determining the effective flavour-changing neutral current couplings qbar-q'-gamma and qbar-q'-g at the next-to-next-to-leading order in QCD. The resulting O(alpha_s^2(mu_b)) correction to the B -> X_s gamma branching ratio amounts to around -2.9% for mu_b = 5 GeV, and -4.4% for mu_b = 2.5 GeV
Keywords
Cite
@article{arxiv.hep-ph/0612329,
title = {Four-Loop Anomalous Dimensions for Radiative Flavour-Changing Decays},
author = {Michal Czakon and Ulrich Haisch and Mikolaj Misiak},
journal= {arXiv preprint arXiv:hep-ph/0612329},
year = {2010}
}
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19 pages