Precise measurement of Br(tau^- -> K^*0(892) K^- nu_tau) and the mass and width of the K^*0(892) meson

Abstract

Using the high statistics tau data sample recorded in the Belle experiment at KEKB, we have greatly improved the precision of the branching fraction Br(tau^- -> K^*0(892) K^- nu_tau) = (1.56+-0.02+-0.09)x10^-3, while the mass and width of the K^*0(892) meson are measured to be (895.10+-0.27+-0.31) MeV/c^2 and (47.23+-0.49+-0.79) MeV/c^2, respectively, with better accuracy than the PDG world average values. The first measurement of the decay tau^- -> K^*0(892) K^- pi^0 nu_tau is also reported with a branching fraction of Br(tau^- -> K^*0(892) K^- pi^0 nu_tau)=(2.39+-0.46+-0.26)x10^-5.