One-prong τ decays with neutral kaons

Abstract

We have analyzed one-prong τ decays with neutral kaons using the information from a fine-grained hadron calorimeter. The data sample consists of 43 500 Z → τ+τ−(γ) events collected by the L3 detector at LEP in 1991, 1992 and 1993. The following branching fractions are measured: B(τ− → ντπ−K0) = 0.0095 ± 0.0015(stat) ± 0.0006(syst); B(τ− → ντπ− π0K0) = 0.0041 ± 0.0012(stat) ± 0.0003(syst) and B(τ− → ντπ−K0K0) = 0.0031 ± 0.0012(stat) ± 0.0004(syst).