B->D*pi+pi-pi-pio, D(*) omega pi- and the Observation of a Wide 1- omega pi- Enhancement at 1418 MeV

We report on the observation of B->D{*}pi+pi-pi-pio decays. The branching ratios for D*+ and D*o are (1.72+/-0.14+/-0.24)% and (1.80+/-0.24+/-0.25)%, respectively. Each final state has a D{*} omega pi- component, with branching ratios (0.29+/-0.03+/-0.04)% and (0.45+/-0.10+/-0.07)% for the D*+ and D*o modes, respectively. We also observe B->D omega pi- decays. The branching ratios for D+ and Do are (0.28+/-0.05+/-0.03)% and (0.41+/-0.07+/-0.04)%, respectively. The omega pi- appears to come from the decay of a wide 1- resonance. A fit to a Breit-Wigner shape gives a mass of 1418+/-26+/-19 MeV and width of 388+/-44+/-32 MeV. We identify this object as the rho(1450) or rho'.