Strange quark mass from flavor breaking in hadronic tau decays - art. no. 093023

The strange quark mass is extracted from a finite energy sum rule (FESR) an alysis of the flavor-breaking difference of light-light and light-strange q uark vector-plus-axial-vector correlators, using spectral functions determi ned from hadronic tau decay data. We point out problems for existing FESR t reatments associated with potentially slow convergence of the perturbative series for the mass-dependent terms in the OPE over certain parts of the FE SR contour, and show how to construct alternate weight choices which not on ly cure this problem, but also (1) considerably improve the convergence of the integrated perturbative series, (2) strongly suppress contributions fro m the region of s values where the errors on the strange current spectral f unction are still large and (3) essentially completely remove uncertainties associated with the subtraction of longitudinal contributions to the exper imental decay distributions. The result is an extraction of m(s) with stati stical errors comparable to those associated with the current experimental uncertainties in the determination of the CKM angle, V-us. We find m(s)(1 G eV) = 158.6+/-18.7+/-16.3+/-13.3 MeV (where the first error is statistical, the second due to that on V-us, and the third theoretical).