${{\boldsymbol \chi}_{{c0}}{(4500)}}$ $I^G(J^{PC})$ = $0^+(0^{+ +})$

This state shows properties different from a conventional ${{\mathit q}}{{\overline{\mathit q}}}$ state. A candidate for an exotic structure. See the review on non- ${{\mathit q}}{{\overline{\mathit q}}}$ states. Seen by AAIJ 2017C in ${{\mathit B}^{+}}$ $\rightarrow$ ${{\mathit \chi}_{{c0}}}{{\mathit K}^{+}}$ , ${{\mathit \chi}_{{c0}}}$ $\rightarrow$ ${{\mathit J / \psi}}{{\mathit \phi}}$ using an amplitude analysis of ${{\mathit B}^{+}}$ $\rightarrow$ ${{\mathit J / \psi}}{{\mathit \phi}}{{\mathit K}^{+}}$ with a significance (accounting for systematic uncertainties) of 6.1 $\sigma $.