M. Battaglia

Measurement of B→Xγ decays and determination of

Using a sample of 383 X 10^6 BB events collected by the BABAR experiment, we measure sums of seven exclusive final states B → X_(d(s))Y, where X_d (Xs) is a nonstrange (strange) charmless hadronic system in the mass range 0:6–1:8 GeV/c^2. After correcting for unmeasured decay modes in this mass range, we obtain a branching fraction for b → dy of (7:2 ± 2:7(stat) ± 2:3(syst) X 10^(-6). Taking the ratio of X_d to X_s we find Г(b → dy)/Г(b → sy) = 0:033 ± 0:013(stat) ± 0:009(syst), from which we determine │V_(td)/V_(ts)│= 0:177 ± 0:043.

Measurements of B→{π,η,η′}lνl branching fractions and determination of

We report measurements of branching fractions for the decays B-->Plnu_{l}, where P are the pseudoscalar charmless mesons pi;{-}, pi;{0}, eta and eta;{}, based on 348 fb;{-1} of data collected with the BABAR detector, using B0 and B+ mesons found in the recoil of a second B meson decaying as B-->D;{(*)}lnu_{l}. Assuming isospin symmetry, we combine pionic branching fractions to obtain B(B;{0}-->pi;{-}l;{+}nu_{l})=(1.54+/-0.17_{(stat)}+/-0.09_{(syst)})x10;{-4}; we find 3.2sigma evidence of the decay B;{+}-->etal;{+}nu_{l} and measure its branching fraction to be (0.64+/-0.20_{(stat)}+/-0.03_{(syst)})x10;{-4}, and determine B(B;{+}-->eta;{}l;{+}nu_{l})<0.47x10;{-4} to 90% confidence level. Using partial branching fractions for the pionic decays in ranges of the momentum transfer and a variety of form factor calculation, we obtain values of the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element |V_{ub}| in ranging from 3.6x10;{-3} to 4.1x10;{-3}.We report measurements of branching fractions for the decays B→P/ν/, where P are the pseudoscalar charmless mesons π-, π0, η and η′, based on 348fb-1 of data collected with the BABAR detector, using B0 and B+ mesons found in the recoil of a second B meson decaying as B→D(*)/ν/. Assuming isospin symmetry, we combine pionic branching fractions to obtain B(B0→π-/+ν/)=(1.54±0. 17(stat)±0.09(syst))×10-4; we find 3.2σ evidence of the decay B+→η/+ν/ and measure its branching fraction to be (0.64±0.20(stat)±0.03(syst))×10-4, and determine B(B+→η′/+ν/)<0.47×10-4 to 90% confidence level. Using partial branching fractions for the pionic decays in ranges of the momentum transfer and a variety of form factor calculation, we obtain values of the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element |Vub| in ranging from 3.6×10-3 to 4.1×10-3.

Measurement of the B → nlv branching fraction and determination of

We report a measurement of the B ->pi center dot nu branching fraction based on 211 fb(-1) of data collected with the BABAR detector. We use samples of B-0 and B+ mesons tagged by a second B meson reconstructed in a semileptonic or hadronic decay and combine the results assuming isospin symmetry to obtain B(B-0 ->pi(-)center dot(+)nu)=(1.33 +/- 0.17(stat)+/- 0.11(syst))x10(-4). We determine the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element vertical bar V-ub vertical bar by combining the partial branching fractions measured in ranges of the momentum transfer squared and theoretical calculations of the form factor. Using a recent lattice QCD calculation, we find vertical bar V-ub vertical bar=(4.5 +/- 0.5(stat)+/- 0.3(syst)0.7/0.5(FF))x10(-3), where the last error is due to the normalization of the form factor.