${{\mathit J / \psi}{(1S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}$ invisible  Decay Mode Summary INSPIRE   JSON  (beta) PDGID:
M070.251
Mode (*) Fraction ($\Gamma_i$ / $\Gamma$) Scale Factor/
Conf. Level		 P(MeV/c)  
$\Gamma_{364}$ ${{\mathit J / \psi}{(1S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}$ invisible $<1.7 \times 10^{-6}$ CL= 90%
Category: Radiative decays
Note: For a narrow state ${{\mathit A}}$ with mass less than 960 MeV.
The following data is related to the above value:
$\Gamma({{\mathit J / \psi}{(1S)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}$ invisible$)/\Gamma_{\text{total}}$
$\Gamma_{364}/\Gamma$