A first prediction of the electromagnetic rare decays ${\eta }^{\prime }\to {\pi }^0\gamma \gamma$ and ${\eta }^{\prime }\to \eta \gamma \gamma$

Rafel Escribano

The branching ratio of the electromagnetic rare decays $\eta \to {\pi }^0\gamma \gamma$ and ${\eta }^{\prime }\to ({\pi }^0,\eta )\gamma \gamma$ are analysed in terms of scalar and vector meson exchange contributions using the fra…