Results on Tau Physics from BaBar

TL;DR

This paper reviews recent tau physics results from BaBar, including limits on lepton-flavor violation, measurements of tau decay branching fractions, and tau lifetime, based on extensive data samples.

Contribution

It provides new upper limits on lepton-flavor violating tau decays and preliminary measurements of tau decay modes and lifetime using large datasets.

Findings

Upper limits on tau->lll decay branching fractions are (1-3) x 10^-7.

Measured tau lifetime is approximately 291 femtoseconds.

Tau decay branching fraction for tau- -> 3h- 2h+ nu is about 8.52 x 10^-4.

Abstract

Recent results on tau physics from BaBar are reviewed. Limits on lepton-flavor violation in the tau decay process tau->lll are presented based on 91.6 fb^1 of data. In all six decay modes considered, the numbers of events found in data are compatible with the background expectations, and upper limits on the branching fractions are set in the range (1-3) 10^-7 at 90% CL. A preliminary measurement of the five prong branching fraction based on 110.7 fb^-1 of data is presented with the result B(tau- -> 3h- 2h+ nu) = (8.52+/-0.09+/-0.40) 10^-4. A preliminary measurement of the tau lifetime based on 30 fb^-1 of data is presented where a lifetime of 290.8+/-1.5+/-1.6 fs is measured.