${{\mathit \eta}_{{{c}}}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit J / \psi}{(1S)}}$  Decay Mode Summary INSPIRE   JSON  (beta) PDGID:
M059.21
Mode Fraction ($\Gamma_i$ / $\Gamma$) Scale Factor/
Conf. Level		 P(MeV/c)  
$\Gamma_{23}$ ${{\mathit \eta}_{{{c}}}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit J / \psi}{(1S)}}$ $<0.018$ CL= 90% 501
The following data is related to the above value:
$\Gamma({{\mathit \eta}_{{{c}}}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit J / \psi}{(1S)}})/\Gamma_{\text{total}}{\times }$ $\Gamma({{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \eta}_{{{c}}}{(2S)}})/\Gamma_{\text{total}}$
$\Gamma_{23}/\Gamma{\times }\Gamma^{{{\mathit \psi}{(2S)}}}_{185}/\Gamma^{{{\mathit \psi}{(2S)}}}$