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

${{\mathit \psi}{(4660)}}$

$I^G(J^{PC})$ = $0^-(1^{- -})$ 

also known as ${{\mathit Y}{(4660)}}$; was ${{\mathit X}{(4660)}}$
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 in radiative return from ${{\mathit e}^{+}}{{\mathit e}^{-}}$ collisions at $\sqrt {s }$ = $9.54 - 10.58$ GeV by WANG 2007D. Also obtained in a combined fit of WANG 2007D, AUBERT 2007S, and LEES 2014F. See also the review on "Spectroscopy of mesons containing two heavy quarks."
${{\mathit \psi}{(4660)}}$ MASS   $4630 \pm6$ MeV (S = 1.4)
${{\mathit \psi}{(4660)}}$ WIDTH   $72 {}^{+14}_{-12}$ MeV (S = 1.7)
$\Gamma_{1}$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$   not seen 2315
$\Gamma_{2}$ ${{\mathit \psi}{(2S)}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$   seen 809
$\Gamma_{3}$ ${{\mathit J / \psi}}{{\mathit \eta}}$   not seen 1192
$\Gamma_{4}$ ${{\mathit D}^{0}}{{\mathit D}^{*-}}{{\mathit \pi}^{+}}$   not seen 1153
$\Gamma_{5}$ ${{\mathit \psi}_{{2}}{(3823)}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$   seen 691
$\Gamma_{6}$ ${{\mathit \chi}_{{c1}}}{{\mathit \gamma}}$   not seen 984
$\Gamma_{7}$ ${{\mathit \chi}_{{c2}}}{{\mathit \gamma}}$   not seen 949
$\Gamma_{8}$ ${{\mathit \Lambda}_{{c}}^{+}}{{\mathit \Lambda}_{{c}}^{-}}$   seen 363
$\Gamma_{9}$ ${{\mathit D}_{{s}}^{+}}{{\mathit D}_{{s1}}{(2536)}^{-}}$   seen 534
$\Gamma_{10}$ ${{\mathit D}_{{s}}^{+}}{{\mathit D}_{{s2}}^{*}{(2573)}^{-}}$    
$\Gamma_{11}$ ${{\mathit \omega}}{{\mathit \pi}^{0}}$   not seen 2247
$\Gamma_{12}$ ${{\mathit \omega}}{{\mathit \eta}}$   not seen 2215