A Study of One-Prong Tau Decays with a Charged Kaon

TL;DR

This paper measures the branching ratios of one-prong tau decays involving charged kaons using ionisation energy loss data from the OPAL detector at LEP, providing precise experimental results near the Z0 resonance.

Contribution

It presents the first detailed measurement of tau decay modes with charged kaons using ionisation energy loss, improving understanding of tau decay channels.

Findings

Branching ratio for tau- -> nu_tau K- >=0h0: 1.528%

Branching ratio for tau- -> nu_tau K-: 0.658%

Results have uncertainties of about 0.04%.

Abstract

From an analysis of the ionisation energy loss of charged particles selected from 110326 e+e- -> tau+tau- candidates recorded by the OPAL detector at e+e- centre-of-mass energies near the Z0 resonance, we determine the one-prong tau decay branching ratios: Br(tau- -> nu_tau K- >=0h0) = 1.528 +- 0.039 +- 0.040 % Br(tau- -> nu_tau K-) = 0.658 +- 0.024 +- 0.029 % where the h0 notation refers to a pi0, an eta, a K^0_S, or a K^0_L, and where the first uncertainty is statistical and the second is systematic.