Measurement of the Branching Fractions of Exclusive B¯→D(*)(π)l-ν¯l Decays in Events with a Fully Reconstructed B Meson

We report a measurement of the branching fractions for B̅ →D(*)(π)ℓ-ν̅ ℓ decays based on 341.1  fb-1 of data collected at the Υ(4S) resonance with the BABAR detector at the SLAC PEP-II e+e- storage rings. Events are tagged by fully reconstructing one of the B mesons in a hadronic decay mode. We obtain B(B-→D0ℓ-ν̅ ℓ)=(2.33±0.09stat±0.09syst)%, B(B-→D*0ℓ-ν̅ ℓ)=(5.83±0.15stat±0.30syst)%, B(B̅ 0→D+ℓ-ν̅ ℓ)=(2.21±0.11stat±0.12syst)%, B(B̅ 0→D*+ℓ-ν̅ ℓ)=(5.49±0.16stat±0.25syst)%, B(B-→D+π-ℓ-ν̅ ℓ)=(0.42±0.06stat±0.03syst)%, B(B-→D*+π-ℓ-ν̅ ℓ)=(0.59±0.05stat±0.04syst)%, B(B̅ 0→D0π+ℓ-ν̅ ℓ)=(0.43±0.08stat±0.03syst)%, and B(B̅ 0→D*0π+ℓ-ν̅ ℓ)=(0.48±0.08stat±0.04syst)%.