Study of τ Decays to Four-Hadron Final States with Kaons

The rare τ lepton decays to four explicitly identified hadrons have been studied with the CLEO detector at the Cornell Electron Storage Ring (CESR) using (7.56±0.15) fb−1 of data collected near . The first statistically significant measurements of B(τ−→K−π+π−π0ντ, excluding K0)=(7.4±0.8±1.1)×10−4 and B(τ−→K−K+π−π0ντ)=(5.5±1.4±1.2)×10−5 are presented, including the first observation of the decay τ−1→K−ωντ with branching fraction, (4.1±0.6±0.7)×10−4. We also publish the first upper limit for at 90% (95%) confidence level (C.L.). We also measure for the first time the invariant mass distributions of the decays.