The $J/\psi D{D}^{\ast }$ vertex

Abstract

We employ QCD sum rules to calculate the $J/\psi D{D}^{\ast }$ form factors and coupling constant by studying the three-point $J/\psi D^{\ast }D$ correlation function. We find that the momentum dependence of the form factor depends on the off-shell meson. We get a value for the coupling which is in agreement with estimates based on constituent quark model.

4 pages, 4 eps figures