The Kpi vector form factor and constraints from Kl3 decays

Abstract

The slope and curvature parameters of the $K\pi$ vector form factor, $F_{+}^{K\pi }$, are fitted to the data on $\tauKpi$ and $K_{l3}$ decays yielding ${\lambda }_{+}^{\prime }=(25.49\pm 0.31)\times 10^{-3}$ and ${\lambda }_{+}"=(12.22\pm 0.14)\times 10^{-4}$. The pole position of the $K^{\ast }(892{)}^{\pm }$ is found to be at $m_{K^{\ast }(892{)}^{\pm }}=892.0\pm 0.5$ MeV and ${\Gamma }_{K^{\ast }(892{)}^{\pm }}=46.5\pm 1.1$ MeV. The phase-space integrals relevant for $K_{l3}$ analyses and the $P$-wave isospin-1/2 $K\pi$ phase-shift threshold parameters are also calculated.

arXiv comment6 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

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Cited by in corpus (3)

• Hadronic currents for ${\tau }^{-}\to {\pi }^{-}{\pi }^0{\nu }_{\tau }$ and other decays of interest in TAUOLA
• Model Independent Electromagnetic corrections in hadronic $\tau$ decays
• V_ud and V_us: CKM 2010 working group I summary