Observation of an anomalous enhancement near the threshold of pp mass spectrum at BES lI BEsJ∧+pp acceptance weighted BW M=1859+3+5MeV/c2 10-25 T<30 Mev/c2(90% cl 100 却地 x/dof=5656 0.1 0.2 0.3 Phys. Rev. Lett. 91,022001(2003) Mpp)-2mp(GeV) 3-body phase space acceptanceObservation of an anomalous enhancement near the threshold of mass spectrum at BES II M=1859 MeV/c 2 G < 30 MeV/c 2 (90% CL) J/pp M(pp)-2mp (GeV) 0 0.1 0.2 0.3 3-body phase space acceptance c2 /dof=56/56 acceptance weighted BW +3 +5 10 25 pp BES II Phys. Rev. Lett. 91, 022001 (2003)