Strange Quark Mass from Tau Lepton Decays with O(alpha_s^3) Accuracy
Abstract
The first complete calculation of the quadratic quark mass correction to the correlator of the two currents relevant for the strangeness-changing semihadronic tau-decay rate is presented including its real part at the four-loop level. This allows to perform the extraction of the strange quark mass m_s from the decay width of the tau-lepton with full O(alpha_s^3) accuracy. In agreement with previous estimates the newly computed alpha_s^3 term proves to be rather large. This justifies inclusion of the similarly estimated alpha_s^4 term in phenomenological analysis. Combined with an updated value of V_{us} and an ``'improved'' version of the renormalization group improvement of the perturbative series this leads to an increase of the central value of m_s by about 20 % and a partial reduction of the theoretical uncertainty by about 50 %.
Keywords
Cite
@article{arxiv.hep-ph/0412350,
title = {Strange Quark Mass from Tau Lepton Decays with O(alpha_s^3) Accuracy},
author = {P. A. Baikov and K. G. Chetyrkin and J. H. Kühn},
journal= {arXiv preprint arXiv:hep-ph/0412350},
year = {2008}
}
Comments
4 pages. References updated. The final version accepted for publication in Physical Review Letters. The complete paper is also available via the www at http://www-ttp.physik.uni-karlsruhe.de/Preprints/