Precision Measurement of anti-B0bar-$>$D*+ Lepton Neutrino Branching Fraction

We present a precision measurement of the exclusive anti-B0 meson decays to D*+, lepton, and anti-neutrino using 476 million B-meson anti-B-meson pairs. The data sample collected with the BABAR detector at the PEP-II asymmetric-energy B-Factory at SLAC National Accelerator Laboratory. The anti-B0 mesons are reconstructed using a partial reconstruction in which the D* four-momentum is inferred from the slow pion. This allows for a much higher statistical precision on this branching fraction. We use a single and double tag method to measure this important branching fraction.