Measurements of the branching fractions and helicity amplitudes in B→D*ρ decays

Using 9.1 fb-1 of e+e- data collected at the Υ(4S) with the CLEO detector using the Cornell Electron Storage Ring, measurements are reported for both the branching fractions and the helicity amplitudes for the decays B-→D*0ρ- and B-bar0→D*+ρ-. The fraction of longitudinal polarization in B-bar0→D*+ρ- is found to be consistent with that in B-bar0→D*+l-ν-bar at q2=Mρ2, indicating that the factorization approximation works well. The longitudinal polarization in the B- mode is similar. The measurements also show evidence of nontrivial final-state interaction phases for the helicity amplitudes