Nature of $X(2370)$

Abstract

We address the nature of the $X(2370)$ resonance observed in the $J/\psi$ radiative decays, $J/\psi \to \gamma K^{+}{K}^{-}{\eta }^{\prime }$, $J/\psi \to \gamma K_S{K}_S{\eta }^{\prime }$ and $J/\psi \to \gamma {\pi }^{+}{\pi }^{-}{\eta }^{\prime }$. By studying the invariant mass spectra we confirm that decays of the $X(2370)$ into three pseudo-scalars are well described by an effective chiral Lagrangian. We extract the branching ratio of $J/\psi \to X(2370)\gamma$ and show that it is an order of magnitude larger compared to the glueball production rate predicted by lattice QCD. This indicates that $X(2370)$ is not likely to be a glueball candidate.

Comments: 5 pages, 2 figures, to be the same as the published version