Width of the gluonic bound state and radiative decay ofψ(J)

Width of the $0^{-}$ gluonic bound state is calculated based on a bound-state equation and is about hundreds MeV if its mass is about 2 GeV. As a consequence of the fact that the decay rate is proportional to the square of the final-quark mass, more than half of the decay states include the $K$ and $\overline{K}$ mesons. An inclusive $\gamma +K$ meson spectrum from $\psi \mathrm{}\left(J\right)\mathrm{}$ is expected to give a signature of the $0^{-}$ gluonic state, even if its width is too large to observe directly.