Title screen

[References: p. 104 (26 tit.)]

We have constructed an isobar model for theη-photoproduction on the proton in the energy region up to the photon lab energy K 0 = 3 GeV. The database involved into the fitting procedure includes precise results for the cross-section and for theT-asymmetry of the processγp→ηpnear threshold obtained at MAMI and ELSA as well as recent results for theΣ-asymmetry and for the angular distribution measured at higher energies in Grenoble and also more recent measurements performed at JLab for the photon energies up to 2 GeV. The model includes twelve nucleon resonances: S 11(1535), S 11(1650), S 11(1825), P 11(1440), P 13(1720), D 13(1520), D15(1675), F 15(1680), F 17(1990), G 17(2190), G 19(2250), H 19(2220), and the background consisting of the nucleon pole term and the vector meson exchange in the t-channel. To explain the observed energy dependence of the integrated cross-section, two s-wave resonances, S 11(1650) and S11(1825), have to be taken into account along with the dominating S 11(1535). The integrated cross-section as well as the angular distribution andΣ-asymmetry predicted by the model are in good agreement with the data. Above the photon energyK 0 = 2 GeV, the calculated cross-section exhibits an appreciable dependence on theρ- andω-meson contribution, whose coupling with nucleons is not well defined. Several versions of extending the model to higher energies are considered.