Polarization observablesΣ,P_y,T₁ in the reaction at photon energies between 200 and 600 MeV and dibaryon resonances

The polarization observables SIGMA, P-gamma, T1, P perpendicular-to gamma, P parallel-to gamma are derived in proton polarization measurements of the gamma --> --> pn --> reaction, using a linearly polarized photon beam of energies between 300 and 600 MeV for c.m.s. proton emission angles of 90-degrees and 120-degrees. A multipole analysis is performed in the framework of the gauge-invariant pole model considering the gamma-N --> pi-N amplitudes and the deuteron structure without dibaryon resonances and with different sets of isovector and isoscalar dibaryon resonances. It is shown that the inclusion of dibaryon resonances substantially improves agreement with experimental data.