Measurement of the Topological Branching Fractions of the τ Lepton

Abstract

We report new and precise measurements of the decay branching fractions of the τ lepton to one and three charged particles. The data, corresponding to an integrated luminosity of 176 pb(−1), were collected by the high resolution spectrometer HRS at the e(+)e(−) storage ring PEP at SLAC operated at s√=29 GeV. The fractions of τ decays into one and three charged particles are 0.869±0.002±0.003 and 0.130±0.002±0.003, respectively.