Measurement of the Tau Lepton Lifetime Using the SLD Detector at the Stanford Linear Collider

The lifetime of the tau lepton is measured to be (2.50 ± 0.35) x 10-14s. The measurement combines the results of two different techniques used on separate samples of tau events collected at the Stanford Linear Collider by the SLD detector during the 1992 physics run. The first technique measures the decay length from the known interaction position to the reconstructed decay vertex position. This requires that the taus have at least three charged decay products. The second technique infers the decay length by correlating the differences in signed impact parameters (for single-charged track decays) with the angles between the tracks