Hidden-charm decays of X(3915) and Z(3930) as the P-wave charmonia

In this work, we investigate the $X\left(3915\right)$ and $Z\left(3930\right)$ decays into $J/\psi \omega$ with the ${\chi }_{c0}^{\prime }\left(2P\right)$ and ${\chi }_{c2}^{\prime }\left(2P\right)$ assignments to $X\left(3915\right)$ and $Z\left(3930\right)$, respectively. The results show that the decay width of $Z\left(3930\right)\to J/\psi \omega$ is at least one order smaller than that of $X\left(3915\right)\to J/\psi \omega$. This observation explains why only one structure, $X\left(3915\right)$, has been observed in the $J/\psi \omega$ invariant mass spectrum for the process $\gamma \gamma \to J/\psi \omega$.