p(γ→,π0) reaction and theE2 excitation of the Δ

Abstract

Results from three independent measurements of the p(γ→,π0) reaction are presented for incident photon energies between 243 and 314 MeV, and for c.m. angles of 105°, 122°, and 150°. The ratio of cross sections measured with orthogonal states of linear polarization is sensitive to the E2 excitation of the Δ resonace. Comparisons are made to the predictions of various models, all of which fail to reproduce these data.