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Title: Measurement of the branching fractions of the radiative leptonic τ decays τ → eγνν¯ and τ → μγνν¯ at BaBar

We perform a measurement of the τ → lγνν¯ (l = e,μ) branching fractions for a minimum photon energy of 10 MeV in the τ rest frame, using 431 fb–1 of e+e collisions collected at the center-of-mass energy of the Υ(4S) resonance with the BABAR detector at the PEP-II storage rings. We find B(τ → μγνν¯) = (3.69±0.03±0.10)×10–3 and B(τ → eγνν¯)=(1.847±0.015±0.052)×10–2, where the first quoted error is statistical and the second is systematic. In addition, these results are substantially more precise than previous measurements.
  1. Univ. de Savoie, CNRS/IN2P3, Annecy-Le-Vieux (France). et al.
Publication Date:
OSTI Identifier:
Report Number(s):
Journal ID: ISSN 1550-7998; PRVDAQ; arXiv:1502.01784
DOE Contract Number:
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles, Fields, Gravitation and Cosmology; Journal Volume: 91; Journal Issue: 5
American Physical Society (APS)
Research Org:
SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Country of Publication:
United States
experiment-HEP; HEPEX