The Kpi vector form factor and constraints from Kl3 decays

Abstract

The slope and curvature parameters of the $Kπ$ vector form factor, $F_+^{Kπ}$, are fitted to the data on $\tauKpi$ and $K_{l3}$ decays yielding $λ_+'=(25.49 \pm 0.31) \times 10^{-3}$ and $λ_+"= (12.22 \pm 0.14) \times 10^{-4}$. The pole position of the $K^*(892)^\pm$ is found to be at $m_{K^*(892)^\pm}= 892.0\pm 0.5$ MeV and $Γ_{K^*(892)^\pm}= 46.5 \pm1.1$ MeV. The phase-space integrals relevant for $K_{l3}$ analyses and the $P$-wave isospin-1/2 $Kπ$ phase-shift threshold parameters are also calculated.

6 pages, uses econfmacros style. Talk presented by R. Escribano at the 6th International Workshop on the CKM Unitarity Triangle (CKM2010), University of Warwick, UK, 6-10 September 2010