Radiative decays $J/\Psi\to\eta^{(\prime)}\gamma$ in perturbative QCD
  With the recent investigations of $g^{\ast}g^{\ast}-\eta^{(\prime)}$ transition form factor and $\eta-\eta^{\prime}$ mixing scheme, we present an updated study of the radiative decays $J/\Psi\to\eta^{(\prime)}\gamma$ in perturbative QCD. The decays are taken as a test ground for the $g^{\ast}g^{\ast}-\eta^{(\prime)}$ transition form factors and the $\eta-\eta^{\prime}$ mixing scheme. The form factors are found to be working for glunic $\eta^{(\prime)}$ productions and the mixing angle is constrained to be $\phi=35.1^{\circ}\pm0.8^{\circ}$. 
Ya-Dong Yang