We calculate the mixing of $\eta$, ${\eta }^{\prime }$, and ${\eta }_c$ in a cylinder-dominated model and apply our results to the hadronic decay ${\psi }^{\prime }\to \psi \eta$ and a number of photonic decays, using vector-meson dominance. The results are in excellent agreement with all experimental data.

• Received 24 May 1976

DOI:https://doi.org/10.1103/PhysRevD.14.1920