τ-lepton branching fractions

Abstract

From a study of $\tau$ decays using the Time Projection Chamber (TPC) detector at the SLAC $e^{+}{e}^{-}$ storage ring PEP, we have measured the one-, three-, and five-charged-particle inclusive branching fractions of the $\tau$ to be (85.2±1.7)%, (14.8±1.7)%, and 0.3%, respectively. Using particle identification by $\frac{\mathrm{dE}}{\mathrm{dx}}$ in the TPC we have searched for charged $K$ mesons in three-prong $\tau$ decays, and have set an upper limit on $B({\tau }^{\pm }\to K^{\pm }+2\mathrm{} \mathrm{c}\mathrm{h}\mathrm{a}\mathrm{r}\mathrm{g}\mathrm{e}\mathrm{d}+\mathrm{n}\mathrm{e}\mathrm{u}\mathrm{t}\mathrm{r}\mathrm{a}\mathrm{l}\mathrm{s})$ of 0.6%.