Observation of a new charmonium state in double charmonium production in e+ e- annihilation at s**(1/2) ~ 10.6-GeV

We report the first observation of a charmoniumlike state recoiling from the $J/\\ensuremath{\\psi}$ in the inclusive process ${e}^{+}{e}^{\\ensuremath{-}}\\ensuremath{\\rightarrow}J/\\ensuremath{\\psi}+\\mathrm{\\text{anything}}$ at a mass of $(3.943\\ifmmode\\pm\\else\\textpm\\fi{}0.006\\ifmmode\\pm\\else\\textpm\\fi{}0.006)\\text{ }\\text{ }\\mathrm{GeV}/{c}^{2}$. We also observe the decay of this state into ${D}^{*}\\overline{D}$ and determine its intrinsic width to be less than $52\\text{ }\\text{ }\\mathrm{MeV}/{c}^{2}$ at the 90% C.L. These results are obtained from a $357\\text{ }\\text{ }{\\mathrm{fb}}^{\\ensuremath{-}1}$ data sample collected with the Belle detector near the $\\ensuremath{\\Upsilon}(4S)$ resonance, at the KEKB asymmetric-energy ${e}^{+}{e}^{\\ensuremath{-}}$ collider.