A subtracted dispersive representation of the Kπ vector form factor, F+Kπ, is used to fit the Belle spectrum of τ→Kπντ decays incorporating constraints from results on Kl3 decays. Through the use of three subtractions, the slope and curvature of F+Kπ are obtained directly from the data yielding λ+'=(25.49±0.31)×10-3 and λ+''=(12.22±0.14)×10-4. The phase-space integrals relevant for Kl3 analyses are calculated. Additionally, from the pole position on the second Riemann sheet the mass and width of the K*(892)± are found to be mK*(892))±=892.0±0.5MeV and ΓK*(892))±=46.5±1.1MeV. Finally, we study the P-wave isospin-1/2 Kπ phase-shift and its threshold parameters. © 2010 Elsevier B.V.
|Journal||Nuclear Physics B - Proceedings Supplements|
|Issue number||1 C|
|Publication status||Published - 1 Oct 2010|
- τ decays
- Dispersion relations
- Kaon decays