Measurement of the branching fractions and the invariant mass distributions for tau^- -> h^-h^+h^-nu_tau decays

TL;DR

This paper measures branching fractions and invariant mass distributions for specific tau decay modes using a large data sample from the Belle detector, providing precise experimental results and insights into tau decay dynamics.

Contribution

The study provides the first precise measurements of branching fractions and invariant mass distributions for tau decays into three-hadron final states.

Findings

Branching fractions for tau decays into three-hadron final states are quantified.

Invariant mass distributions for these decays are unfolded and analyzed.

Results improve understanding of tau decay mechanisms.

Abstract

We present a study of tau->pipipinu, tau->Kpipinu, tau->KKpinu, and tau->KKKnu decays using a 666 fb-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(tau->pipipinu) = (8.42+-0.01+0.26-0.25) x 10^-2, B(tau->Kpipinu) = (3.30+-0.01+0.16-0.17) x 10^-3, B(tau->KKpinu) = (1.55+-0.01+0.06-0.05) x 10^-3, and B(tau->KKKnu) = (3.29+-0.17+0.19-0.20) x 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 pi^+pi^- pair originates from a Ks decay. We also present the unfolded invariant mass distributions for these decays.