Decay properties of tau leptons measured at the Z0 resonance

From 2540 Z0 → τ+τ- events, we determine the inclusive decay branching fractions of the τ-lepton into one and three charged particles to be 0.856 ± 0.006 (stat.) ± 0.003 (syst.) and 0.144 ± 0.006 (stat.) ± 0.003 (syst.), respectively. The leptonic branching fractions are measured to be 0.175 ± 0.008 (stat.) ± 0.005 (syst.) for τ → μνμντ and 0.177 ± 0.007 (stat.) ± 0.006 (syst.) for τ → eνeντ. We determine the τ lifetime both from three-prong decays using the decay length and from one-prong decays using the impact parameter. The results from the two independent methods agree and yield a combined value of [0.309 ± 0.023 (stat.) ± 0.030 (syst.)]x10-12 0s. (orig.)