also known as ${{\mathit Y}{(4360)}}$; was ${{\mathit X}{(4360)}}$
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 AUBERT 2007S, WANG 2007D, and LEES 2014F. See also the review on "Spectroscopy of mesons containing two heavy quarks."