An optical interpretation of polarization parameters

The simplicity of the language of optics in discussing experiments with polarized beams and/or polarized targets is stressed and a semi-classical model which permits simple calculations of polarization and spin-correlation parameters for general spins is presented. The assumptions that nucleons interact primarily diffractively, and that the only spin dependence of the interaction arises from a weak spin-orbit force, leads to a simple model for all the nucleon polarization and spin-correlation parameters which is consistent with the available data. A number of predictions are given for future experiments, and possible tests of the model are noted. The relation between the s-channel optical language and the t-channel exchange language is also discussed. It is shown that several features of the Regge exchange picture (suppression of unnatural parity exchanges, approximate factorization of the amplitude, and the presence of weak cuts) are natural consequences of the model. (Auth.)