Strange quark, tachyonic gluon masses and vertical bar V-us vertical bar from hadronic tau decays

摘要

We apply, to the new OPAL data on V + A strange spectral functions, a suitable combination of QCD spectral sum rules directly sensitive to the combination of strange quark (m(s)) and tachyonic gluon (gimel(2)) masses. Using the mean value of gimel(2) from a sum rule analysis of different channels, we deduce the invariant strange quark mass (m) over cap (s) = (106(-37)(+33)) MeV to order alpha(s)(3), which leads to the running mass (m) over cap (s) (2 GeV) = (93(-32)(+29)) MeV. We also obtain an interesting though less accurate estimate of the CKM angle: vertical bar V(us)vertical bar = 0.217 +/- 0.019. (c) 2005 Elsevier B.V. All rights reserved.