ar X iv : h ep - p h / 06 11 18 0 v 1 1 3 N ov 2 00 6 The joint extraction of m s and V us from hadronic τ decay data

The joint extraction of m s and V us 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 K ℓ3 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. Measurements of the inclusive hadronic τ decay distributions for processes mediated by the flavor ij = ud, us vector (V) or axial vector (A) currents yield kinematically weighted linear combinations of the spectral functions, ρ (J) V /A;ij , of the spin J = 0 and 1 parts of the relevant current-current correlators, Π