Skip to main content
Open Access Publications from the University of California

UC Irvine

UC Irvine Previously Published Works bannerUC Irvine

Measurement of the branching fractions of the τ lepton using a tagged sample of τ decays


The branching fractions for the major decay modes of the lepton are measured from a sample of tagged decays selected from +- pairs produced in e+e- annihilation. The decay products of one member of the +- pair are used to identify the event. The opposite member of the pair is then included in the sample if it satisfies an invariant-mass cut and a charged-multiplicity cut. In this way, we attempt to select an unbiased sample of decays. The sample is divided into categories based on charged- and neutral-particle multiplicities, and charged-particle identification. The branching fractions are measured simultaneously, with an unfold technique and a maximum-likelihood fit, with the sum of the branching fractions constrained to be unity. The branching fractions for the decay modes - K- and - K*- are fixed at the world averages in the fit. The following branching fractions are measured: B(-e) =(, B(-' - )=(, B(-) =(10.01.1 *1,4)%, B(-0) =(, B(-(n0, n>1))=(, B(-+-) =(6.7 0.80.9)%, and B(-+- (n0,n>0)) =( The total branching fraction to one charged pion plus at least one neutral hadron is measured to be ( Limits on allowed decay modes involving the meson are discussed. © 1987 The American Physical Society.

Many UC-authored scholarly publications are freely available on this site because of the UC's open access policies. Let us know how this access is important for you.

Main Content
For improved accessibility of PDF content, download the file to your device.
Current View