Narrow Results

In this talk, I would report the new observation of X(1835), which has properties inconsistent with any know mesons, but consistent with expectations for the state that produces the strong mass threshold enhancement observed in the process at BESII. I will also review some other multiquark candidates which are indicated by and mass threshold enhancements.

A new resonance X(1835) in the J/psi radiative decays, a couple of significant enhancements near threshold, and clear evidences for a broad 1^-- resonant structure of K⁺K^-, the σ and κ mesons in the J/psi hadronic decays from BES are reported. Favored interpretations of these observations are discussed.

Results based on 106 M ψ′ events and about 226 M J/ψ events acquired with the BESIII detector at BEPCII are reported, including a confirmation of the BESII threshold enhancement in , branching ratios for χ_cJ → π⁰π⁰ and ηη, and first measurements of the branching ratios for ψ′ → π⁰h_c and h_c → γη_c, as well as measurements of the mass and width of the h_c.