Measurement of Γee(J/ψ), Γtot(J/ψ), and Γee[ψ(2S)]/Γee(J/ψ)

Abstract

Using data acquired with the CLEO detector at the CESR e+e- collider at s=3.773GeV, we measure the cross section for the radiative return process e+e-→γJ/ψ, J/ψ→μ+μ-, resulting in B(J/ψ→μ+μ-)×Γee(J/ψ)=0.3384±0. 0058±0.0071keV, Γee(J/ψ)=5.68±0.11±0.13keV, and Γtot(J/ψ)=95.5±2.4±2.4keV, in which the errors are statistical and systematic, respectively. We also determine the ratio Γee[ψ(2S)]/Γee(J/ψ)=0.45±0.01±0.02. © 2006 The American Physical Society.