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

${{\boldsymbol Z}_{{c}}{(3900)}}$ $I^G(J^{PC})$ = $1^+(1^{+ -})$ 

was ${{\mathit X}{(3900)}}$
Properties incompatible with a ${{\mathit q}}{{\overline{\mathit q}}}$ structure (exotic state). See the review on non- ${{\mathit q}}{{\overline{\mathit q}}}$ states. Charged ${{\mathit Z}_{{c}}{(3900)}}$ seen as a peak in the invariant mass distribution of the ${{\mathit J / \psi}}{{\mathit \pi}^{\pm}}$ system by BES III (ABLIKIM 2013T) in ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit J / \psi}}$ at c.m. energy of 4.26 GeV and by radiative return from ${{\mathit e}^{+}}{{\mathit e}^{-}}$ collisions at $\sqrt {s }$ from 9.46 to 10.86 GeV at Belle (LIU 2013B). Partial wave analysis of ABLIKIM 2017J determines $\mathit J{}^{P} = 1{}^{+}$ with more than 7$~\sigma $ significance. Neutral ${{\mathit Z}_{{c}}{(3900)}}$ seen in the ${{\mathit J / \psi}}{{\mathit \pi}^{0}}$ invariant mass distribution in ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{0}}{{\mathit \pi}^{0}}{{\mathit J / \psi}}$ at c.m. energies of 4.23, 4.26, and 4.36 GeV by BES III (ABLIKIM 2015U) and at 4.17 GeV by XIAO 2013A. Peaks in ( ${{\mathit D}}{{\overline{\mathit D}}^{*}}$ )${}^{0,\pm{}}$ reported by BES III (ABLIKIM 2014A, ABLIKIM 2015AB) are assumed to be related.
${{\mathit Z}_{{c}}{(3900)}}$ MASS   $3888.4 \pm2.5$ MeV (S = 1.7)
${{\mathit Z}_{{c}}{(3900)}}$ WIDTH   $28.3 \pm2.5$ MeV 
$\Gamma_{1}$ ${{\mathit J / \psi}}{{\mathit \pi}}$  seen 700
$\Gamma_{2}$ ${{\mathit h}_{{c}}}{{\mathit \pi}^{\pm}}$  not seen 319
$\Gamma_{3}$ ${{\mathit \eta}_{{c}}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$  not seen 760
$\Gamma_{4}$ ${{\mathit \eta}_{{c}}{(1S)}}{{\mathit \rho}{(770)}^{\pm}}$ 
$\Gamma_{5}$ ( ${{\mathit D}}{{\overline{\mathit D}}^{*}}$) ${}^{+-}$  seen
$\Gamma_{6}$ ${{\mathit D}^{0}}{{\mathit D}^{*-}}$ + c.c.  seen 160
$\Gamma_{7}$ ${{\mathit D}^{-}}{{\mathit D}^{*0}}$ + c.c.  seen 152
$\Gamma_{8}$ ${{\mathit \omega}}{{\mathit \pi}^{\pm}}$  not seen 1863
$\Gamma_{9}$ ${{\mathit J / \psi}}{{\mathit \eta}}$  not seen 511
$\Gamma_{10}$ ${{\mathit D}^{+}}{{\mathit D}^{*-}}$ + c.c  seen
$\Gamma_{11}$ ${{\mathit D}^{0}}{{\overline{\mathit D}}^{*0}}$ + c.c  seen