Inclusive J$\psi$ production in $e^+ e^-$ annihilation in the energy range from 4.0-GeV to 5.0-GeV

(1977). doi:10.1016/0370-2693(77)90289-1
We report on inclusive production of J ψ (3.1)-mesons observed in e + e − -annihilation in the energy range s = 4.0–5.0 GeV . After substraction of the radiative tail of the ψ(3.7) direct production of the J ψ (3.1) is found to be in the order of 0.1% of the total hadronic cross section. No enhancements are seen at s = 4.03 GeV and 4.4 GeV. The level is in agreement with expectations from violation of the Zweig-rule.