Wang, YM (reprint author), Inst High Energy Phys, POB 918 4, Beijing 100049, Peoples R China.
Within the standard model, we investigate the semi-leptonic weak decays of J/psi. The various form factors of J/psi making the transition to a single charmed meson (D-(d,D-s)(*)) are studied in the framework of QCD sum rules. These form factors fully determine the rates of the weak semi-leptonic decays of J/psi and provide valuable information on non-perturbative QCD effects. Our results indicate that the decay rate of the semi-leptonic weak decay mode J/psi -> D-s(*)(-) + e(+) + nu(e) is at the order of 10(-10).