Download or read book Measurement of Branching Fractions and Form Factor Parameters of B-]Dlnu and B-]D*lnu Decays at BaBar written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We use a global fit to determine the form factor slopes and branching fractions of the decays B --> Dlnu and B --> D*lnu. We reconstruct Dl pairs and construct a 3-dimensional distribution binned in lepton momentum, D momentum and cosTheta(B-Dl). These kinematic variables provide good separation between the signal and background. We fit electron and muon samples separately and combine them after calculating systematic uncertainties. The form factor slopes, rhoD^2 for B --> Dlnu and rho^2 for B --> D*lnu decays, are measured to be rhoD^2 = 1.22 +- 0.04 +- 0.07 and rho^2 = 1.21 +- 0.02 +- 0.07, where the errors are statistical and systematic, respectively. Branching fractions are fitted to be B(B+ --> D0lnu) = (2.36 +- 0.03 +- 0.12) % and B(B^+ --> D*0lnu) = (5.37 +- 0.02 +- 0.21) %. We use these results to determine the products, G(1)|Vcb| = (43.8 +- 0.8 +- 2.3)*10^{-3} and F(1)|Vcb| = (35.7 +- 0.2 +- 1.2)*10^{-3} of the form factors at zero recoil and the CKM matrix element |Vcb|, from which |Vcb| can be extracted using theoretical input.