${\mathit {\mathit c}}$ ${\mathit {\overline{\mathit c}}}$ MESONS
(including possibly non- ${\mathit {\mathit q}}$ ${\mathit {\overline{\mathit q}}}$ states)

${{\mathit X}{(4100)}^{\pm}}$

$I^G(J^{PC})$ = $1^-(?^{? ?})$ 
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 
$\Gamma_{1}$ ${{\mathit \eta}_{{c}}{(1S)}}{{\mathit \pi}^{-}}$   seen 953
$\Gamma_{2}$ ${{\mathit \pi}^{\pm}}{{\mathit \psi}{(3770)}}$   not seen 279