The first observation of $\tau^{\pm} \to \phi K^{\pm} \nu$ decay

TL;DR

This paper reports the first observation of the tau decay into a phi meson, a kaon, and a neutrino, using Belle experiment data, and measures its branching ratio with high precision.

Contribution

It provides the first measurement of the tau decay to a phi meson and a kaon, expanding understanding of tau hadronic decay modes.

Findings

First observation of $ au^{ pm} o phi K^{ pm} u$ decay.

Measured branching ratio: (4.06 ± 0.25 ± 0.26)×10^{-5}.

Data from 401.4 fb$^{-1}$ of Belle experiment.

Abstract

We present the first measurement of tau-decays to hadronic final states with a $\phi$-meson. This is based on 401.4 fb$^{-1}$ of data accumulated at the Belle experiment. The branching ratio obtained is $B(\tau^{\pm}\to\phi K^{\pm}\nu) = (4.06\pm 0.25\pm 0.26)\times 10^{-5}$.