ISSN - 15507998, Physical Review D - Particles, Fields, Gravitation and Cosmology, 2010, vol. 81, p. -
Measurement of the branching fractions and the invariant mass distributions for τ-→h-h+h-ντ decays
We present a study of τ-→π -π+π-ντ, τ -→K-π+π-ντ, τ-→K-K+π-ντ, and τ-→K-K+K-ντ decays using a 666fb-1 data sample collected with the Belle detector at the KEKB asymmetric-energy e+e- collider at and near a center-of-mass energy of 10.58 GeV. The branching fractions are measured to be B(τ-→π-π+π -ντ)=(8.42±0.00-0.25+0.26)×10-2, B(τ-→K-π+π-ντ) =(3.30±0.01-0.17+0.16)×10-3, B(τ -→K-K+π-ντ)=(1. 55±0.01-0.05+0.06)×10-3, and B(τ -→K-K+K-ντ)=(3. 29±0.17-0.20+0.19)×10-5, where the first uncertainty is statistical and the second is systematic. These branching fractions do not include contributions from modes in which a π+π- pair originates from a KS0 decay. We also present the unfolded invariant mass distributions for these decays. © 2010 The American Physical Society.