| We report a study of tau lepton decays to three charged hadrons and a pi0. We use (7.56 +/- 0.15) fb -1 of data collected with the CLEO III detector at the Upsilon(4 S) resonance, which corresponds to a total of (6.90 +/- 0.14) x 106 tau-pairs. Using both a Ring Imaging Cherenkov (RICH) detector and measurement of specific ionization energy loss ( dE/dx) for particle identification, we report the first observation of the decay tau- → K -oupsilontau. We report the first statistically significant measurements of the branching fractions for tau- → K-pi+pi -pi0upsilontau (excluding K0), tau- → K -K+pi -pi0upsilontau and the first published upper limit for tau- → K -K+K -pi0upsilontau. We also measure branching fractions for the decays, tau- → h-oupsilontau, tau - → pi-oupsilontau, tau - → h-h +h-pi0upsilon tau, and tau- → pi-pi +pi-pi0upsilon tau. |
