Perspective study of charmonium and exotics above DD¯ threshold

AbstractThe spectroscopy of exotic states with hidden charm is discussed. Together with charmonium it is a good testing tool for theories of strong interactions including QCD in both perturbative and non-perturbative regime, lattice QCD, potential models and phenomenological models. An elaborated analysis of exotics spectrum is given, and attempts to interpret recent experimental data in the above DD¯ threshold region are considered. Experimental data from different collaborations (BES, BaBar, Belle, LHCb) are analyzed with special attention given to new states with hidden charm which were discovered recently. Some of these states can be interpreted as higher-lying charmonium states and tetraquarks with hidden charm. It has been shown that charge/neutral tetraquarks must have their neutral/charge partners with mass values differ by few MeV. This hypothesis coincides with that proposed by Maiani and Polosa. But much more data on different decay modes are needed before firmer conclusions can be made. These data can be derived directly from the experiments using the high quality antiproton beam with momentum up to 15 GeV/c and proton-proton collisions with momentum up to 26 GeV/c