Polarization phenomena in nucleon-nucleon forward scattering

The interference between strong and electromagnetic interactions is investigated in detail for close-to-forward nucleon-nucleon scattering in the intermediate-energy region. No specific assumptions are made concerning the strong-interaction amplitudes. The electromagnetic ones are calculated in the one-photon approximation, by taking the usual nucleon form factors into account. Higher-order electromagnetic corrections as well as the simultaneous exchange of photons and mesons are approximated by the relative Coulomb phase (for pp scattering). Higher-order effects are ignored in np scattering, however, a sixth amplitude, violating isospin invariance and due to electromagnetic interactions, is accounted for systematically. Formulae are presented for all np and pp experimental quantities involving at most two spin projections. Numerical predictions are made on the basis of previous phase-shift analyses and the obtained formulae. They are presented on graphs. The results can be used in the planning of future NN experiments and in the analysis of the data obtained. (author)