Photoreactions in Few Body Systems: Polarization Experiments

Some of the most recent results obtained at the LEGS-BNL facility in the field of photonuclear reactions using polarized photons are reviewed. Sensitivity to E2 excitation of the a stimulated the study of pi(0) photoproduction and Compton scattering on the proton. Inclusive and exclusive photo-disintegrations of He-3 have also been measured in order to investigate the role of 3-body correlation effects, being He-3 the simplest nucleus where these effects may be present. The measurement of coherent photon scattering on He-4 has been performed to provide significative constraints to the reaction mechanism and to extract information on the creation and the propagation of the Delta in nuclear matter. General characteristics of polarized photon beams obtained by the backscattering of Laser light against high energy electrons circulating in storage rings are presented; the possibility of studying Kaon photoproduction on proton at the GRAAL facility, by measuring the beam and the Lambda polarization observables together with the cross-section, is investigated