Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China
; Chinese Acad Sci, Grad Sch, Beijing 100049, Peoples R China
; Nankai Univ, Dept Phys, Tianjin 300071, Peoples R China
; Guangxi Normal Univ, Dept Phys, Guilin 541004, Peoples R China
By solving the complex Schrodinger equation with the phenomenological Paris optical potential between nucleon(N) and antinucleon((N) over bar), the near-threshold binding and resonant behaviors of the p-(p) over bar system are studied. As the result, a P-13(0) resonance state of p (p) over bar is obtained. It is found that the energy and width of the state are compatible with the BES data in which the observed enhancement in the J/psi ->gamma pp decay was fitted by a Breit-Wigner (B-W) formula either in the S-wave or in the P-wave. The indication of the results and the suggestion for the further theoretical investigation are discussed.