Precise measurement of hadronic tau-decays with an eta meson

Abstract

We have studied hadronic tau decay modes involving an eta meson using 490 fb(-1) of data collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. The following branching fractions have been measured B(tau(-) -> K-eta nu(tau)) = (1.58 +/- 0.05 +/- 0.09) x 10(-4), B(tau(-) -> K-pi(0)eta nu(tau)) = (4.6 +/- 1.1 +/- 0.4) x 10(-5), B(tau(-) -> pi(-)pi(0)eta nu(tau)) = 1.35 +/- 0.03 +/- 0.07)x10(-3), B(tau(-)-> pi K--(S)0 eta nu(tau)) = 4.4 +/- 0.7 +/- 0.2) x 10(-5) and B(tau(-) -> K*(-) eta nu(tau)) = (1.34 +/- 0.12 +/- 0.09) x 10(-4). These result are substantially more precise than previous measurements. The new measurements are compared with theoretical calculations based on the CVC hypothesis or the chiral pertubation theory. We also set upper limits on branching fractions for tau decays into (K-KS0)eta nu(tau), pi K--(S)0 pi(0)eta nu(tau), K-eta eta nu(tau), pi(-)eta eta nu(tau) and non-resonant K-pi(0)eta nu(tau) final states (C) 2009 Published by Elseiver B.V.