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

${{\boldsymbol \psi}{(4660)}}$ $I^G(J^{PC})$ = $0^-(1^{- -})$ 

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   $4633 \pm7$ MeV (S = 1.4)
${{\mathit \psi}{(4660)}}$ WIDTH   $64 \pm9$ MeV 
$\Gamma_{1}$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$  not seen 2316
$\Gamma_{2}$ ${{\mathit \psi}{(2S)}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$  seen 812
$\Gamma_{3}$ ${{\mathit J / \psi}}{{\mathit \eta}}$  not seen 1194
$\Gamma_{4}$ ${{\mathit D}^{0}}{{\mathit D}^{*-}}{{\mathit \pi}^{+}}$  not seen 1156
$\Gamma_{5}$ ${{\mathit \chi}_{{c1}}}{{\mathit \gamma}}$  not seen 986
$\Gamma_{6}$ ${{\mathit \chi}_{{c2}}}{{\mathit \gamma}}$  not seen 952
$\Gamma_{7}$ ${{\mathit \Lambda}_{{c}}^{+}}{{\mathit \Lambda}_{{c}}^{-}}$  seen 371
$\Gamma_{8}$ ${{\mathit D}_{{s}}^{+}}{{\mathit D}_{{s1}}{(2536)}^{-}}$  seen 539