Onψ′→Jψ+ηand related questions

The decay process ${\psi }^{\prime }\to \psi \eta$ is regarded as an Okubo-Zweig-Iizuka (OZI) rule violating transition since we assume no a priori admixture of $c\overline{c}$ quarks in $\eta$. Unitarity corrections to the OZI rule are computed within the context of dual model and found to be roughly two orders of magnitude larger than in the case of ${\psi }^{\prime }\to \rho \pi$. Using the vector-dominance model the radiative decays $\psi \to \eta \gamma$ and $\psi \to {\eta }^{\prime }\gamma$ are investigated. Dynamical violations of SU(3) introduced by the mass difference between charmed mesons in the same SU(3) multiplet are adequate to explain the experimentally observed ratio $\frac{\Gamma (\psi \to \eta \gamma )}{\Gamma (\psi \to {\eta }^{\prime }\gamma )}$.