OPTICAL MODEL POTENTIAL FOR PION-NUCLEUS SCATTERING

Our object is to carry out an optical model study of the elastic scattering of pions from nuclei using the multiple scattering formalism of Watson. This treatment includes only the 1st order and 2nd order contributions. The second order optical potential involves two-body correlations of which we are primarily interested in those due to Pauli principle. We have obtained results for the two-body correlation functions for 6Li, 12C, 160, and lf0Ca based on the shell model, using single-particle wavefunctions generated from a potential of the Saxon-Wood type or from the Harmonic Oscillator potential. The extent to which these differ is discussed. We have also considered the effect of the Fermi-motion of the target nucleons on the ttN forward scattering amplitudes. Using the optical model potential so derived, we have obtained the total reaction crosssections for 208Pb and 12C within the momentum ran^e 0.7 <P < 2 GeV/c. TT The theoretical predictions have been compared with the available data to obtain information on the neutron distributions in nuclei.