Measurement of the (B)over-bar->Dl(nu)over-bar partial width and form factor parameters

Abstract

We have studied the decay (B) over bar --> Dl<(nu)over bar>, where I = e or mu. From a fit to the differential decay rate d Gamma/dw we measure the rate normalization F-D (1)\V-cb\ and form factor slope <(rho)over cap>(2)(D), and, using measured values of tau(B), find Gamma(B --> Dl<(nu)over bar>) = (12.0 +/- 0.9 +/- 2.1) ns(-1). The resulting branching fractions are B((B) over bar(0) --> D(+)l(-)<(nu)over bar>) = (1.87 +/- 0.15 +/- 0.32)% and B(B- --> D(0)l(-)<(nu)over bar>) = (1.94 +/- 0.15 +/- 0.34)%. The form factor parameters are in agreement with those measured in B --> D*l<(nu)over bar> decays, as predicted by heavy quark effective theory.