Measurement of the tau -lepton lifetime.

Abstract

We report a new and precise measurement of the lifetime of the τ lepton. The data were taken with the High Resolution Spectrometer at the SLAC e+e− colliding-beam facility PEP operating at 29 GeV center-of-mass energy. The flight distances of 1311 τ decays to three charged particles were measured with a four-layer tubular-cell vertex chamber in conjunction with the main drift chamber. The resulting lifetime of the τ lepton is ττ=(2.99±0.15±0.10)×10−13 sec.Received 27 April 1987DOI:https://doi.org/10.1103/PhysRevLett.59.2519©1987 American Physical Society