η and η' meson photoproduction on nucleons

Meson photoproduction on nucleons is considered within an approach based on a multipole analysis. The results of a decade-long theoretical investigation of η and η' meson photoproduction on nucleons are discussed with the aim of gaining information about N resonances in experimental data. With an ongoing accumulation and refinement of experimental data, the number of known resonances used to analyze γp → ηp reactions was reduced from 12 to 6. However, S ₁₁(830) and D ₁₅(2150) resonances not included in the PDG compilation were found to be needed in those analyses. Precise measurements of differential cross sections of η meson photoproduction on protons carried out at the Mainz microtron offered the opportunity to specify the properties of S ₁₁(1535) resonance. The same theoretical approach has been used to analyze experimental data on the cross sections of γp → η'p reactions obtained by CLAS-2009 and Mainz collaborations. The description of the cross sections for this reaction with only nucleon resonances taken into account was found to be satisfactory up to the photon energy of 3700 MeV.