Extraction of Neutron Density Distributions from Proton Elastic Scattering at Intermediate Energies

Cross sections, analyzing powers and spin rotation parameters of proton elastic scattering from ⁵⁸Ni and ¹²⁰Sn have been measured at 200-400 MeV. Obtained data have been analyzed in the framework of relativistic impulse approximations. In order to explain the ⁵⁸Ni data, it was necessary to modify NN interactions in the nuclear medium by changing coupling constants and masses of σ and ω mesons. For ¹²⁰Sn, by assuming the same modification of NN interactions and by using proton densities deduced from charge densities, the neutron density distribution was searched so as to reproduce ¹²⁰Sn data at 300 MeV.