Select physics solution via $eta$-$eta$ mixing

A novel and simple method is proposed to select the physics solution in the decays of $Y(4230) to eta J/psi$ and $Y(4230) to eta J/psi$, where multiple solutions have been reported in the experimental measurements. Based on an $eta$-$eta$ mixing analysis, unique solutions are determined for the two measurements, respectively. Furthermore, this analysis also indicates $Y(4230)$ would not contain substantial $sbar{s}$ quark component.