Coupling constant for the J/ψDsDs vertex from QCD sum rules

The coupling constant of the meson vertex J/ψDsDs is calculated using the three point correlation function within the QCD sum rules formalism. We have considered alternately mesons J/ψ and Ds off-shell together with non-perturbative contributions up to the mixed quark-gluon condensates. When extrapolated, these two different form factors give the same coupling constant for the process gJ/ψDsDs=5.98−0.58+0.67.