π+π−π0Decay of 1138ηMesons Produced inK−,p→Λ, ηnear Threshold

Abstract

The Dalitz plot density of $\eta \to {\pi }^{+}{\pi }^{-}{\pi }^0$ is examined. We find the asymmetry on the ${\pi }^{\pm }$ energies to be $A=\frac{(N^{+}-N^{-})}{(N^{+}+N^{-})}=-0.014\mathrm{}\pm 0.030$, where $N^{\pm }$ is the number of events for which $T_{\mp }>T_{\mp }$. The density is well fitted with a linear dependence on $T_0:{\mathrm{}\left|M\right|\mathrm{}}^2\propto 1+2\alpha \left[\right(\frac{3T_0}{Q})-1]$, with $\alpha =-0.47\mathrm{}\pm 0.04$.