Study of polarization observables in double-pion photoproduction on the proton Original Research Article

Using a model for two-pion photoproduction on the proton previously tested in total cross sections and invariant mass distributions, we evaluate here polarization observables on which recent experiments are providing new information. We evaluate cross sections for spin 1/2 and 3/2, which have been measured at Mainz and play an important role in tests of the GDH sum rule. We also evaluate the proton polarization asymmetry Σ which is currently under investigation at GRAAL in Grenoble.