Abstract:

Based on a prior effective Lagrangian model on single pion photoproduction from the nucleon, successfully tested in total and differential cross sections, the helicity dependence from the interaction of circularly polarized photons and a longitudinally polarized nucleon target is studied in the energy range from p-threshold through the D(1232)-resonance region. The doubly polarized total and differential cross section differences for parallel s3/2 and antiparallel s1/2 helicity states are predicted and compared with recent experimental data. We show that the results are sensitive to interferences among different contributions to the process and, thus, represent a complementary test of the theoretical model. A quite satisfactory agreement with recent experimental data from the GDH-collaboration is obtained.

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