Recent N^* Results From J/ψDecays

Abstract

Based on 7.8 million J/ψevents collected at BEPC, the events for J/ψ\to p\bar{p}π^0 and p\bar{p}ηhave been selected and reconstructed. Clear peaks are observed around 1480 MeV in pπ^0 (\bar{p}π^0) invariant mass spectrum and near the threshold for $η$ production in pη(\bar{p}η) invariant mass spectrum. A partial wave analysis of J/ψ\to p\bar{p}ηdata has been performed. Two J^P={1/2}^- resonances are observed with mass and width (M, Γ) at (1540^{+15}_{-17}, 178^{+20}_{-22}) MeV and (1648^{+18}_{-16}, 150)MeV, and are considered to be the nucleon resonances S_{11}(1535) and S_{11}(1650) respectively.