$\eta \to {\pi }^0\gamma \gamma$ to $\mathcal{O}(p{)}^6$ in Chiral Perturbation Theory

M. Jetter

The decay $\eta \to {\pi }^0\gamma \gamma$ is discussed in the framework of SU(3) chiral perturbation theory. The process is dominated by the $\mathcal{O}(p^6)$ in the momentum expansion where tree-lev…