Some meson coupling constants in broken SU(4) and the radiative decays ofψandηc

Abstract

We calculate vector-pseudoscalar-pseudoscalar and vector-vector-pseudoscalar coupling constants in broken SU(4) using current algebra and partial conservation of the axial-vector current. As applications of our results, estimates of the decay widths $\Gamma (\psi \to X^0\gamma )$, $\Gamma (\psi \to {\eta }_c\gamma )$, and $\Gamma ({\eta }_c\to 2\gamma )$ are presented.