New cross sections for the reaction ep → epη are reported for total center of mass energy W = 1.5-1.86 GeV and invariant momentum transfer Q2 = 0.25-1.5 (GeV/c)2. This large kinematic range allows extraction of important new information about response functions, photocouplings, and ηN coupling strengths of baryon resonances. Newly observed structure at W ∼ 1.65 GeV is shown to come from interference between S and P waves and can be interpreted with known resonances. Improved values are derived for the photon coupling amplitude for the S11 (1535) resonance.
ASJC Scopus subject areas
- Physics and Astronomy(all)