η mesons emitted from the photoproduction off protons were measured for 0.70≤Eγ≤1.15 GeV. The γp→ηp reaction process was separated from the πηp final state by the momentum difference of η mesons for Eγ≥930 MeV. The angular distributions obtained and the excitation function of the γp→ηp reaction are essentially in good agreement with previously reported ones and are well explained by η-MAID calculations. For the γp→πηN reaction, the cross section increases monotonically with increasing photon energy, and it almost reaches the value of the γp→ηp reaction at Eγ~1.15 GeV. The momentum distributions are compared with kinematic calculations. It is suggested that the sequential decay process through the P33(1232) resonance [γp→η P33(1232)→πηN] contributes to the γp→πηN reaction, in addition to the sequential process γp→πS11(1535) →πηN and/or π and η emissions without intermediate nucleon resonances.
ASJC Scopus subject areas
- Nuclear and High Energy Physics