Charged Kaon Production in Tau Lepton Decays

[摘要]

The result of an experiment performed at the PEP e⁺e^- storage ring whichoperated at 29.0 GeV/c² is presented. The DELCO detector, which emphasizesCherenkov particle identification, is used to measured the production of chargedkaons in τ decays. The branching ratio of the Cabibbo-suppressed decays b(τ^± →K^± ν_τ) = (0.57 ± 0.15)%, b(τ^± → K^± ν_τ + nπ⁰) = (1.59 ± 0.23)% n ≥ 0, andb(τ^± → K^±π⁺π^-ν_τ(π⁰)) = (0.22^+0.16_-0.13)% are measured, and the branching ratioof the Cabibbo-favored decay b(τ^± → K⁺K^-π^±ν_τ) = (0.22^+0.17_-0.11)% is measured.These branching ratio measurements provide a test e - µ - τ universality and arein agreement with and the predictions of SU(3) sum rules. The invariant massdistribution of the K⁺K^-π system in the exclusive τ^± → K⁺K^-π^±ν_τ channel isused to set a limit of 157 MeV/c² at 95% CL on the τ neutrino mass.

[发布机构] University:California Institute of Technology;Department:Physics, Mathematics and Astronomy

[关键词] Physics