Obtaining the strong coupling constants g_(J/psi D_s D_s) and g_(φ D_s D_s) from QCD Sum Rules

The form factors and coupling constants of the meson vertices J/\psi D_s D_s and \phi D_s D_s were calculated using three point correlation functions within the QCD Sum Rules formalism. We have considered the cases where \phi, D_s and J/\psi mesons are off-shell obtaining, for each vertex, two different form factors and its corresponding coupling constants, namely g_{J/\psi D_s D_s} = 6.20^{+0.97}_{-1.15} and g_{\phi D_s D_s} = 1.85^{+0.22}_{-0.23}.