${{\mathit J / \psi}{(1S)}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}{{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$  Decay Mode Summary INSPIRE   JSON  (beta) PDGID:
M070.473
Mode Fraction ($\Gamma_i$ / $\Gamma$) Scale Factor/
Conf. Level		 P(MeV/c)  
$\Gamma_{9}$ ${{\mathit J / \psi}{(1S)}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}{{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ ($3.53$ $\pm0.26$) $ \times 10^{-5}$ 1545
The following data is related to the above value:
$\Gamma({{\mathit J / \psi}{(1S)}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}{{\mathit \mu}^{+}}{{\mathit \mu}^{-}})/\Gamma_{\text{total}}$
$\Gamma_{9}/\Gamma$