2012/07/03 by BABAR Collaboration, J. P. Lees, V. Poireau +98 · 2 citations
Physics and Astronomy · #Annihilation #Branching fraction #Electron #Hadron #Lepton #Neutrino Physics Research #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #hep-ex
paper · pdf · doi:10.1103/physrevd.88.031102
8 pages, 10 figures, submitted to Phys. Rev. D (Rapid Communications)
arxiv created 2012/07/03 · openalex publication_date 2013/08/08 · arxiv updated 2013/08/14 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
We present a search for the decay B+\ensuremath→\ensuremathτ+\ensuremathν using 467.8\ifmmode×\else\texttimes\fi106 BB pairs collected at the \ensuremathΥ(4S) resonance with the BABAR detector at the SLAC PEP-II B-Factory. We select a sample of events with one completely reconstructed B^\ensuremath- in the hadronic decay mode (B^\ensuremath-\ensuremath→D(*)0X^\ensuremath- and B^\ensuremath-\ensuremath→J/\ensuremathψX^\ensuremath-). We examine the rest of the event to search for a B+\ensuremath→\ensuremathτ+\ensuremathν decay. We identify the \ensuremathτ+ lepton in the following modes: \ensuremathτ+\ensuremath→e+\ensuremathν\ensuremathν, \ensuremathτ+\ensuremath→\ensuremathμ+\ensuremathν\ensuremathν, \ensuremathτ+\ensuremath→\ensuremathπ+\ensuremathν and \ensuremathτ+\ensuremath→\ensuremathρ+\ensuremathν. We find an excess of events with respect to the expected background, which excludes the null signal hypothesis at the level of 3.8\ensuremathσ (including systematic uncertainties) and corresponds to a branching fraction value of B(B+\ensuremath→\ensuremathτ+\ensuremathν)=(1.83_\ensuremath-0.49+0.53(stat)\ifmmode±\else\textpm\fi0.24(syst))\ifmmode×\else\texttimes\fi10^\ensuremath-4.