We study the interplay between charge symmetry breaking and renormalization in the NN system for S-waves. We find a set of universality relations which disentangle explicitly the known long distance dynamics from low energy parameters and extend them to the Coulomb case. We analyze within such an approach the One-Boson-Exchange potential and the theoretical conditions which allow to relate the proton-neutron, proton-proton and neutron-neutron scattering observables without the introduction of extra new parameters and providing good phenomenological success.

Two consequences of charge symmetry breaking (CSB) in the n-p system are examined. In n-p elastic scattering, CSB nuclear forces cause a difference between the polarizations of the neutron and the proton scattered in opposite directions in the center of mass system. The expected differences in polarizations due to one boson exchanges, particularly a photon exchange, isospin mixed mesons, and a pion (with the n-p mass difference taken into account), are computed. The calculated polarization difference is typically of the order of several tenths of a percent. In np .-->. d.pi.°, the CSB of nuclear forces can be tested by measuring the asymmetry of the angular distribution of deuterons about 90° in the center of mass frame. The expected asymmetry is calculated for one boson exchange CSB mechanisms, as in the elastic scattering. The asymmetry caused by the mixed n-.pi.° exchange is dominant, but all of the mechanisms contribute asymmetries with similar angular dependences. The maximum assymmetry is about 0.8% at °; the average is about 0.2%.