2006/07/31 by The BABAR Collaboration, B. Aubert, R. Barate +98
Mathematics · Physics and Astronomy · #Algorithm #B meson #Branching fraction #Hadron #High-Energy Particle Collisions Research #Isospin #Lepton #Mathematics #Meson #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Semileptonic decay #hep-ex
paper · pdf · doi:10.1103/physrevlett.97.211801
published as Phys.Rev.Lett.97:211801,2006 · 8 pages (including EPAPS), 4 postscript figures
arxiv created 2006/11/21 · openalex publication_date 2006/11/21 · arxiv updated 2010/03/19 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
We report a measurement of the B\ensuremath→\ensuremathπ\ensuremathℓ\ensuremathν branching fraction based on 211 fb^\ensuremath-1 of data collected with the BABAR detector. We use samples of B0 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(B0\ensuremath→\ensuremathπ^\ensuremath-\ensuremathℓ+\ensuremathν)=(1.33\ifmmode±\else\textpm\fi0.17stat\ifmmode±\else\textpm\fi0.11syst)\ifmmode×\else\texttimes\fi10^\ensuremath-4. We determine the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element |Vub| 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 |Vub|=(4.5\ifmmode±\else\textpm\fi0.5stat\ifmmode±\else\textpm\fi0.3syst\genfrac0+0.7\ensuremath-0.5FF)\ifmmode×\else\texttimes\fi10^\ensuremath-3, where the last error is due to the normalization of the form factor.