The decay tau(-) --> 2 pi(-)pi(+)3 pi(0) nu(tau) has been studied with the CLEO II detector at the Cornell Electron Storage Ring. The branching fraction is measured to be (2.85 +/- 0.56 +/- 0.51) x 10(-4). The result is in good agreement with the isospin expectation but somewhat below the conserved-vector-current prediction. We have searched for resonance substructure in the decay. Within the statistical precision, the decay is saturated by the channels tau(-) --> pi(-)2 pi(0) omega nu(tau), 2 pi(-)pi(+)eta nu(tau), and pi(-)2 pi(0) eta nu(tau). This is the first observation of this omega decay mode and the branching fraction is measured to be (1.89(-0.67)(+0.74) +/- 0.40) x 10(-4).
Anderson, S, Kubota, Y, et al. Study of the decay tau(-)->2 pi(-)pi(+)3 pi(0)nu(tau). PHYSICAL REVIEW LETTERS. November 1997. 79(20) : 3814-3818