Energy dependence of proton polarization in the γ+p → π+p reaction in the second resonance range at an angle of 90 deg in the center-of-mass system

The energy dependence of proton polarization in the γ+p → π+p reaction under 90 deg in the center-of-mass system has been investigated in the range of photon energies 540-640 MeV. The measurements have been taken in order to obtain systematic and reliable information for the above energy range. The experiment is carried out with a telescope film spark chambers and a magnetic spectrometer. Proton polarization has been determined from the asymmetry of scattering in graphite electrodes of the spark chamber. The polarization values obtained show satisfactory agreement with the results of a phenomenological analysis