## Abstract

The product of the electronic width of the ψ(2S) meson and the branching fraction of its decay to the muon pair was measured in the e+e→ψ(2S)→μ+μ process using nine data sets corresponding to an integrated luminosity of about 6.5 pb−1 collected with the KEDR detector at the VEPP-4M electron–positron collider: Γee×Bμμ=19.3±0.3±0.5eV. Adding the previous KEDR results on hadronic and leptonic channels, the values of the ψ(2S) electronic width were obtained under two assumptions: either with the assumption of lepton universality Γee=2.279±0.015±0.042keV or without it, summing up hadronic and three independent leptonic channels Γee=2.282±0.015±0.042keV.

Original language English 174-181 8 Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 781 https://doi.org/10.1016/j.physletb.2018.03.079 Published - 10 Jun 2018

## Keywords

• Branching fraction
• Leptonic width
• ψ(2S) meson
• GENERATOR
• MASSES
• J/PSI-MESON
• ANNIHILATION
• KEDR DETECTOR
• psi(2S) meson
• MONTE-CARLO
• WIDTHS