We present measurements of the branching fractions for J/ψ→e+e- and μ+μ- using 3M ψ(2S) decays collected with the CLEO detector operating at the CESR e+e- collider. We obtain B(J/ψ→e+e-)=(5. 945±0.067±0.042)% and B(J/ψ→μ+μ-)=(5.960±0. 065±0.050)%, leading to an average of B(J/ψ→+-)=(5.953±0. 056±0.042)% and a ratio of B(J/ψ→e+e-)/B(J/ψ→μ+μ- )=(99.7±1.2±0.6)%, all consistent with, but more precise than, previous measurements.
|Original language||English (US)|
|Journal||Physical Review D - Particles, Fields, Gravitation and Cosmology|
|State||Published - Jun 1 2005|
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Physics and Astronomy (miscellaneous)