Measurements of the semileptonic decays (B)over-bar -> Dl(nu)over-bar and (B)over-bar -> D*l(nu)over-bar using a global fit to DXl(nu)over-bar final states

Semileptonic B[overbar] decays to DXlν[overbar](l=e or μ) are selected by reconstructing D^0l and D^+l combinations from a sample of 230×10^6 Υ(4S)→BB[overbar] decays recorded with the BABAR detector at the PEP-II e^+e^- collider at SLAC. A global fit to these samples in a three-dimensional space of kinematic variables is used to determine the branching fractions B(B^-→D^0lν[overbar])=(2.34±0.03±0.13)% and B(B^-→D^(*0)lν[overbar])=(5.40±0.02±0.21)% where the errors are statistical and systematic, respectively. The fit also determines form-factor parameters in a parametrization based on heavy quark effective theory, resulting in ρ_D^2=1.20±0.04±0.07 for B[overbar]→Dlν[overbar] and ρ_(D*)^2=1.22±0.02±0.07 for B[overbar]→D^*lν[overbar]. These values are used to obtain the product of the Cabibbo-Kobayashi-Maskawa matrix element |V_(cb)| times the form factor at the zero recoil point for both B[overbar]→Dlν[overbar] decays, G(1)|V_(cb)|=(43.1±0.8±2.3)×10^(-3), and for B[overbar]→D^*lν[overbar] decays, F(1)|V_(cb)|=(35.9±0.2±1.2)×10^(-3).