${{\boldsymbol \eta}^{\,'}{(958)}}$ $\rightarrow$ invisible INSPIRE search

$\Gamma($ ${{\mathit \eta}^{\,'}{(958)}}$ $\rightarrow$ invisible$)/\Gamma($ ${{\mathit \eta}^{\,'}{(958)}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$ $)$
$\Gamma_{29}/\Gamma_{7}$
M002R44
$\Gamma($ ${{\mathit \eta}^{\,'}{(958)}}$ $\rightarrow$ invisible$)/\Gamma($ ${{\mathit \eta}^{\,'}{(958)}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \eta}}$ $)$
$\Gamma_{29}/\Gamma_{1}$
M002R09
$\Gamma($ ${{\mathit \eta}^{\,'}{(958)}}$ $\rightarrow$ invisible$)/\Gamma_{\text{total}}$
$\Gamma_{29}/\Gamma$
M002R52