${\boldsymbol {\boldsymbol c}}$ ${\boldsymbol {\overline{\boldsymbol c}}}$ MESONS(including possibly non- ${\boldsymbol {\boldsymbol q}}$ ${\boldsymbol {\overline{\boldsymbol q}}}$ states) INSPIRE search

# ${{\boldsymbol X}{(4100)}^{\pm}}$ $I^G(J^{PC})$ = $1^-(?^{? ?})$

Properties incompatible with a ${{\mathit q}}{{\overline{\mathit q}}}$ structure (exotic state). See the review on non- ${{\mathit q}}{{\overline{\mathit q}}}$ states. Reported by AAIJ 2018AN in the ${{\mathit \eta}_{{c}}{(1S)}}{{\mathit \pi}^{-}}$ invariant mass distribution in ${{\mathit B}^{0}}$ $\rightarrow$ ${{\mathit \eta}_{{c}}{(1S)}}{{\mathit K}^{+}}{{\mathit \pi}^{-}}$ decays with a significance of 3.4$\sigma$. $\mathit J{}^{P} = 0{}^{+}$ or ${}^{}1{}^{-}$ assignment consistent with data.
 ${{\mathit X}{(4100)}^{\pm}}$ MASS $4096 \pm28$ MeV
 ${{\mathit X}{(4100)}^{\pm}}$ WIDTH $152 {}^{+80}_{-70}$ MeV