High-Energy Optical Potential and Nuclear Correlations

The high-energy elastic scattering of nucleons by nuclei is studied using the optical-potential operator provided by Watson's multiple-scattering theory. The main motivation is to investigate the possibility of detecting two-body correlations in terms of an optical potential. We have obtained an expression for the second-order potential in coordinate space which explicitly exhibits its nonlocality in terms of the two-body correlations arising from the Pauli principle and the repulsive core of the nucleon-nucleon interaction. We have performed a self-consistent analysis of the elastic scattering of 1-GeV protons on ⁴He using a reasonable nucleon-nucleon scattering amplitude, the one-body density obtained from elastic electron scattering, and a parametrization for the two-body density consistent with the one-body density and dependent upon a parameter identifiable as a correlation length. We have also attempted to discriminate among several sets of nucleon-nucleon phase shifts at 630 MeV. The scattering of 1-GeV protons by ¹²C and ¹⁶O is studied in order to investigate the relative importance of Pauli and short-range correlations. We also critically compare our work with that of several others.