Neutron-Proton Scattering and Pion Theory of Nuclear Forces

The n-p scattering at 90 MeV is discussed in detail from the standpoint of reference 1) . Around this energy phase shifts with ~2 are almost completely determined by the one-pion.·exchange poten· tial. Phase shifts with L= 1 should be qualitatively determined by the pion theory. Phase shifts with L=O must be determined phenomenologically. In this paper, using P-wave phase shifts obtained by Otsuki from the p-p scattering data, we determine scattering parameters in the (] = 1) ·states from the n-p scattering analysis. In section 2, n-p polarizations are analyzed and some sets of phase shifts with 1 which are consistent with the experiments are determined. Using thus determined phase shifts, angular distributions are calculated and compared with experimental data in. section 3. Thus we find that the static pion-theoretical potential can reproduce n·p experimental data at 90 MeV without any serious modifications.