2003/07/23 by B. Aubert, R. Barate, D. Boutigny +97 · 5 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex
paper · pdf · doi:10.1103/physrevlett.92.071802
published as Phys.Rev.Lett.92:071802,2004 · Submitted to Phys. Rev. Lett
arxiv created 2003/07/23 · openalex publication_date 2004/02/18 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/04
We report a measurement of the inclusive charmless semileptonic branching fraction of B mesons in a sample of 89\ifmmode×\else\texttimes\fi106 BB events recorded with the BABAR detector at the \ensuremathΥ(4S) resonance. Events are selected by fully reconstructing the decay of one B meson and identifying a charged lepton from the decay of the other B meson. The number of signal events is extracted from the mass distribution of the hadronic system accompanying the lepton and is used to determine the ratio of branching fractions B(B\ensuremath→Xu\ensuremathℓ\ensuremathν)/B(B\ensuremath→X\ensuremathℓ\ensuremathν)=[2.06\ifmmode±\else\textpm\fi0.25(stat)\ifmmode±\else\textpm\fi0.23(syst)\ifmmode±\else\textpm\fi0.36(theo)]\ifmmode×\else\texttimes\fi10^\ensuremath-2. Using the measured branching fraction for inclusive semileptonic B decays, we find B(B\ensuremath→Xu\ensuremathℓ\ensuremathν)=[2.24\ifmmode±\else\textpm\fi0.27(stat)\ifmmode±\else\textpm\fi0.26(syst)\ifmmode±\else\textpm\fi0.39(theo)]\ifmmode×\else\texttimes\fi10^\ensuremath-3 and derive the Cabibbo-Kobayashi-Maskawa matrix element |Vub|=[4.62\ifmmode±\else\textpm\fi0.28(stat)\ifmmode±\else\textpm\fi0.27(syst)\ifmmode±\else\textpm\fi0.48(theo)]\ifmmode×\else\texttimes\fi10^\ensuremath-3.