The joint extraction of ms and Vus from hadronic τ decay data

We discuss the simultaneous determination of ms and Vus from flavor-breaking hadronic τ decay sum rules, focussing on weight choices designed to better control problems associated with the slow convergence of the relevant integrated D=2 OPE series. The results are found to display improved stability and consistency relative to those of conventional analyses based on the “(k,0) spectral weights”. The results for ms agree well with those of recent strange scalar sum rule and strange pseudoscalar sum rule and lattice analyses. Results for Vus agree within errors with those of lattice-input-based Γ[Kμ2]/Γ[πμ2] and Kℓ3 analyses. Very significant error reductions are shown to be expected, especially for Vus, once improved strange spectral data from the B factory experiments becomes available.