One-prong tau decays with kaons

TL;DR

This paper measures branching ratios of one-prong tau decays involving kaons using data from the ALEPH detector, providing detailed insights into decay modes and dynamics.

Contribution

It presents new measurements of tau decay branching ratios involving kaons, including both inclusive and exclusive modes, with improved precision and analysis of decay dynamics.

Findings

Measured inclusive branching ratio B(tau- -> K-Xnu_tau) = (1.52 +- 0.04 +- 0.04)%

Determined several exclusive decay mode branching ratios with uncertainties

Provided upper limits for certain rare decay modes

Abstract

One-prong tau decays into final states involving kaons are studied with about 161k tau+tau- events collected by the ALEPH detector from 1991 to 1995. Charged kaons are identified by dE/dx measurement, while K0L's are detected through their interaction in calorimeters. Branching ratios are measured for the inclusive mode, B(tau- -> K-Xnu_tau)=(1.52 +- 0.04 +- 0.04)%, where X can be any system of neutral particles, and for the exclusive modes B(tau- to K- nu_tau) = (6.96 =- 0.25 +- 0.14)x 10-3, B(tau- to K- pi0 nu_tau) = (4.44 +- 0.26 +- 0.24)x 10-3, B(tau-to K- pi0 pi0 nu_tau)= (0.56 +- 0.20 +- 0.15) x 10-3, B(tau- to K- pi0 pi0 pi0 nu_tau = (0.37 +- 0.21 +- 0.11) x 10-3, B(tau- to K-K0 nu_tau) = (1.62 +- 0.21 +- 0.11) x 10-3, B(tau- to K-K0 pi0 nu_tau) = (1.43 +- 0.25 +- 0.21)x 10-3, B(tau- to \overline{K0} pi- nu_tau) = (9.28 +- 0.45 +- 0.34)x 10-3, B(tau- to \overline{K0} pi-pi0 nu_tau) = (3.47 +- 0.53 +- 0.37) x 10-3. Upper limits for B(tau- to \overline{K0} pi- pi0 pi0 nu_tau) and B(tau- to K- K0 pi0 pi0 nu_tau are also obtained. Mass spectra in the final states are addressed in order to study the relevant dynamics.