Measurement of the decay tau(-) -> pi(-) pi(+) pi(-) 2pi(0)nu-tau

Abstract

The decay tau- --> pi-pi+pi-2pi0nu(tau) has been observed in e+e- annihilation using the CLEO II detector at the Cornell Electron Storage Ring. In a data sample collected at square-root s is similar to 10.6 GeV, 668 +/- 38 decay candidates have been identified by exclusively reconstructing two pi0,s accompanying three charged particles, which are assumed to be pions. Normalizing to the number of tau pairs detected with one charged particle recoiling against three charged particles, this yields a branching ratio of B3pi2pi0 = (0.48 +/- 0.04 +/- 0.04)%. A signal of 430 +/- 33 events for the decay tau- --> pi-omegapi0nu(tau) has also been observed, corresponding to a branching ratio of B(piomegapi)0=(0.39 +/- 0.04 +/- 0.04)%.