1998/06/10 by J. Z. Bai, J. G. Bian, I. Blum +97 · 23 citations
Physics and Astronomy · #Dark Matter and Cosmic Phenomena #Lepton #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #hep-ex
paper · pdf · doi:10.1103/physrevd.58.092006
published in Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 58(9) (American Physical Society) · Eleven pages with three figures
arxiv created 1998/06/10 · openalex publication_date 1998/10/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
A comparison of the rates for \ensuremathψ(2S)\ensuremath→\ensuremathπ+\ensuremathπ^\ensuremath-J/\ensuremathψ, J/\stackrel\ensuremath→\ensuremathψl+l^\ensuremath- and J/\stackrel\ensuremath→\ensuremathψ anything is used to determine the J/\ensuremathψ leptonic branching fractions. The results are B(J/\stackrel\ensuremath→\ensuremathψe+e^\ensuremath-)=(5.90\ifmmode±\else\textpm\fi0.05\ifmmode±\else\textpm\fi0.10)% and B(J/\stackrel\ensuremath→\ensuremathψ\ensuremathμ+\ensuremathμ^\ensuremath-)=(5.84\ifmmode±\else\textpm\fi0.06\ifmmode±\else\textpm\fi0.10)%, where the first error is statistical and the second is systematic. Assuming lepton universality, the leptonic branching fraction of the J/\ensuremathψ is B(J/\stackrel\ensuremath→\ensuremathψl+l^\ensuremath-)=(5.87\ifmmode±\else\textpm\fi0.04\ifmmode±\else\textpm\fi0.09)% per species. This result is used to estimate the QCD scale factor \ensuremathΛ_MS\ifmmode\else\textasciimacron\fi(4) and the strong coupling constant \ensuremathαs.