2001/02/12 by M. N. Achasov, М. Н. Ачасов, K. Beloborodov +46 · 2 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex
paper · pdf · doi:10.1103/physrevlett.86.1698
published as Phys.Rev.Lett.86:1698-1701,2001 · RevTeX, 5 pages, 3 figures. To be published in Phys. Rev. Lett
arxiv created 2001/02/12 · openalex publication_date 2001/02/26 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The process e+e^\ensuremath-\ensuremath→\ensuremathμ+\ensuremathμ^\ensuremath- has been studied by the SND detector at the VEPP-2M e+e^\ensuremath- collider in the \ensuremathφ(1020)-resonance energy region. The measured effective \ensuremathφ meson leptonic branching ratio B(\ensuremathφ\ensuremath→l+l^\ensuremath-)\ensuremath≡√B(\ensuremathφ\ensuremath→e+e^\ensuremath-)B(\ensuremathφ\ensuremath→\ensuremathμ+\ensuremathμ^\ensuremath-)\phantom\rule0ex0ex=\phantom\rule0ex0ex(2.89\ifmmode±\else\textpm\fi0.10\ifmmode±\else\textpm\fi0.06)\ifmmode×\else\texttimes\fi10^\ensuremath-4 agrees well with the Particle Data Group value B(\ensuremathφ\ensuremath→e+e^\ensuremath-)\phantom\rule0ex0ex=\phantom\rule0ex0ex(2.91\ifmmode±\else\textpm\fi0.07)\ifmmode×\else\texttimes\fi10^\ensuremath-4, confirming \ensuremathμ- e universality. Without additional assumption of \ensuremathμ- e universality the branching ratio B(\ensuremathφ\ensuremath→\ensuremathμ+\ensuremathμ^\ensuremath-)\phantom\rule0ex0ex=\phantom\rule0ex0ex(2.87\ifmmode±\else\textpm\fi0.20\ifmmode±\else\textpm\fi0.14)\ifmmode×\else\texttimes\fi10^\ensuremath-4 was obtained.