New measurement of B -> D*pi branching fractions

The decays Y(4S) → ̄BB, followed by B → D* π and D* → Dπ, permit reconstruction of all kinematic quantities that describe the sequence without reconstruction of the D. with reasonably low backgrounds. Using an integrated e+ e- luminosity of 3.1 fb-1 accumulated at the Y(4S) by the CLEO-II detector, we report measurements of B(̄0B → D*+ π-) = (2.81 ± 0.11 ± 0.21 ± 0.05) × 10-3 and B(B → D*0 π) = (4.34 ± 0.33 ± 0.34 ± 0.18) × 10-3.