Constraining the Kπ vector form factor by and decay data

✍ Scribed by Diogo R. Boito; Rafel Escribano; Matthias Jamin

• Book ID: 103868985
• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 177 KB
• Volume: 207-208
• Category: Article
• ISSN: 0920-5632
• DOI: 10.1016/j.nuclphysbps.2010.10.038

✦ Synopsis

A subtracted dispersive representation of the Kπ vector form factor, F Kπ + , is used to fit the Belle spectrum of τ → Kπν τ decays incorporating constraints from results on K l3 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 K l3 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 m K * (892) ± = 892.0 ± 0.5 MeV and Γ K * (892) ± = 46.5 ± 1.1 MeV. Finally, we study the P-wave isospin-1/2 Kπ phase-shift and its threshold parameters.