We have measured the ratios $\frac{({\eta }^0\to \mathrm{neutral}\mathrm{decay}\mathrm{modes})}{({\eta }^0\to \mathrm{charged}\mathrm{decay}\mathrm{modes})}$ and $\frac{({\eta }^0\to {\pi }^{+}{\pi }^{-}\gamma )}{(\eta \to {\pi }^{+}{\pi }^{-}{\pi }^0)}$ to be, respectively, 2.64 ± 0.23 and 0.28 ± 0.04. By combining these ratios with the results of the preceding Letter for the neutral modes, we obtain partial decay rates for the various ${\eta }^0$ decays. In particular, we obtain $\frac{({\eta }^0\to 3{\pi }^0)}{({\eta }^0\to {\pi }^{+}{\pi }^{-}{\pi }^0)}=1.58\mathrm{}\pm 0.25$, in good agreement with the assumption that the three-pion final state has $I=1\mathrm{}$.

• Received 10 November 1967

DOI:https://doi.org/10.1103/PhysRevLett.19.1498