huang yanping (IHEP)
The decays of psi'-> pi pi J/psi (J/psi -> gamma p pbar), psi'-> gamma ppbar, J/psi-> gamma p pbar, J/psi -> gamma pi pi eta’ and J/psi -> omega pi pi eta are analyzed using the samples of 2.26 X 10^8 J/psi events and 1.06 X 10^8 psi' events collected with the BESIII detector. In psi'-> pi pi J/psi (J/psi -> gamma p pbar) decay, an enhancement at p pbar threshold is observed. The enhancement can be fit with an S-wave Breit-wigner resonances function with a mass of M=1861+6-13(stat)+7-26(syst) MeV/c2 and a narrow width Gamma < 38 MeV/c2 at the 90% confidence level. A similar structure is also observed in J/psi->gamma p pbar. These results are consistent with published BESII results. The mass and width of this structure do not match with any well established mesons. No similar narrow structure is seen in psi'->gamma p pbar. For the decays of J/psi->gamma pi pi eta', the resonance X(1835), which was observed at BESII in the same decays, is confirmed in both of the two decay modes of eta’ ( eta' -> gamma rho and eta’ -> pi pi eta). Besides, the hint for two new additional structures is revealed. The search for possible new structure in J/psi -> omega pi pi eta has also been performed.