Polarization of Recoil Protons from the Photoproduction of Eta-Meson

Abstract

The polarization of recoil protons from the reaction γ+ p → p +η 0 was measured for eta center of mass angle of 107.5° at 890 MeV γ-ray energy. The decay γ-rays from η 0 were detected by a lead glass Cerenkov counter in coincidence with a recoil proton. Recoil proton polarization was measured by analysing the scattering asymmetry in a carbon plate spark chamber. According to Minami's theoretical analysis for the interpretation of the eta-nucleon system, the obtained value of the polarization P =0.54±0.40 is suggesting that the contribution of the interaction in the S 1/2 state is predominant over that in the D 3/2 state.