Published November 24, 2006 | Version v1
Journal article

Measurement of the B→πlν Branching Fraction and Determination of vertical bar Vub vertical bar with Tagged B Mesons

  • 1. Laboratoire de Physique des Particules, F-74941 Annecy-le-Vieux (France)
  • 2. Universitat de Barcelona, Facultat de Fisica Dept. ECM, E-08028 Barcelona (Spain)
  • 3. Universita di Bari, Dipartimento di Fisica and INFN, I-70126 Bari (Italy)
  • 4. Institute of High Energy Physics, Beijing 100039 (China)
  • 5. University of Bergen, Institute of Physics, N-5007 Bergen (Norway)

Description

We report a measurement of the B→πlν branching fraction based on 211 fb-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→π-l+ν)=(1.33±0.17stat±0.11syst)x10-4. 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 vertical bar Vub vertical bar =(4.5±0.5stat±0.3syst(+0.7/-0.5)FF)x10-3, where the last error is due to the normalization of the form factor

Additional details

Publishing Information

Journal Title
Physical Review Letters
Journal Volume
97
Journal Issue
21
Journal Page Range
p. 211801-211801.7
ISSN
0031-9007
CODEN
PRLTAO

Optional Information

Notes
(c) 2006 The American Physical Society
Collaborations
BABAR Collaboration