Determination of [V-ub] from tagged and untagged B(B)over-bar events with the BABAR detector

摘要

Measurements of charmless semileptonic B-meson decays and the CKM matrix element vertical bar V(ub)vertical bar are reported based on a sample of 88 million B (B) over bar events recorded with the BABAR detector. Decays B -> X(u)lv are selected from both tagged and untagged B (B) over bar events and separated from the dominant charm background, B -> X(c)lv, using different kinematic variables: the lepton momentum E-l, the squared four-momentum transfer q(2), and the hadronic mass m(X). The extrapolation to the total decay rate to determine vertical bar V(ub)vertical bar is performed for different theoretical models. We have also measured branching ratios for the exclusive semileptonic decays B -> pi(rho, omega, eta, eta', a(0))l nu, where a high signal purity is reached by fully or partially reconstructing the second B(.)meson.