Measurement of the B¯→Dlv¯ partial width and form factor parameters

Abstract

We have studied the decayB¯→Dlν¯ where l = e or μ. From a fit to the differential decay ratedγ/dwwe measure the rate normalizationFD(1) |V cb | and form factor slopeρˆ2D, and, using measured values ofτB, findγ(B¯→Dlv¯) = (12.0 ± 0.9 ± 2.1) ns−1 . The resulting branching fractions areB (B¯0 → D+ l−ν¯) = (1.87 ± 0.15 ± 0.32)% and B (B− → D0l−ν¯) = (1.94 ± 0.15 ± 0.34)% . The form factor parameters are in agreement with those measured in B¯ → D*l−ν¯ decays, as predicted by heavy quark effective theory. © 1997 The American Physical Society.