Measurement of the pseudoscalar mixing angle and ${\eta }^{\prime }$ gluonium content with KLOE detector

The KLOE Collaboration, F. Ambrosino

We have measured the ratio $R_{\varphi }=BR(\varphi \to {\eta }^{\prime }\gamma )/BR(\varphi \to \eta \gamma )$ by looking for the radiative decays $\varphi \to {\eta }^{\prime }\gamma$ and $\varphi \to \eta \gamma$ in the final states ${\pi }^{+}{\pi }^{-}$ 7 $\gamma$'s and 7…