Measurement of the Matrix Elements for the Decays $\eta \to {\pi }^{+}{\pi }^{-}{\pi }^0$ and $\eta /{\eta }^{\prime }\to {\pi }^0{\pi }^0{\pi }^0$

M. Ablikim, M. N. Achasov, X. C. Ai +413

Based on a sample of $1.31\times 10^9$ $J/\psi$ events collected with the BESIII detector at the BEPCII collider, Dalitz plot analyses of selected 79,625 $\eta \to {\pi }^{+}{\pi }^{-}{\pi }^0$…