Precise measurement of hadronic $τ$-decays in modes with $η$ mesons

Abstract

We have measured branching fractions of hadronic $τ$ decays involving an $η$ meson using 485 fb^{-1} of data collected with the Belle detector at the KEKB asymmetric-energy e^+e^- collider. We obtain the following branching fractions: ${\cal B}(τ^-\to K^- ην_τ)=(1.62\pm 0.05 \pm 0.09)\times 10^{-4}$, ${\cal B}(τ^-\to K^- π^0 ην_τ) =(4.7\pm 1.1 \pm 0.4)\times 10^{-5}$, ${\cal B}(τ^-\to π^- π^0 ην_τ)=(1.39 \pm 0.03 \pm 0.07) \times 10^{-3}$, and ${\cal B}(τ^-\to K^{*-} ην_τ)=(1.13\pm 0.19 \pm 0.07)\times 10^{-4}$ improving the accuracy compared to the best previous measurements by factors of six, eight, four and four, respectively.

BELLE-CONF-0714; contributed to EPS 2007 and Lepton Photon 2007