SOME THEORETICAL ISSUES OF HADRON PRODUCTIONS AND PROPERTIES FROM J/ψ DECAYS

J/ψ strong decay is one of the best places to study the hadronic structure and the strong interaction. In this talk, as the background contribution, the proton pole diagram contribution to the branching ratio and the angular distribution in decays is analyzed. The applicability of quark models is explored via process. The structures of N*s, especially Roper resonance, are discussed by studying J/ψ decays. The productions of possible multi-quark systems via charmonium and bottomonium strong/radiative decays are also investigated.