Nucleon scattering from light nuclei: (I). The targets 6Li and 7Li

Abstract

New data for the elastic and inelastic scattering of 24.4 MeV protons from 6, 7Li are presented and a summary of all the available data for the elastic, inelastic, and charge exchange scattering of 24–50 MeV protons from these same targets is given. The cross-section data for E p ≅25 and 50 MeV are examined theoretically within the framework of the microscopic folding model and the distorted-wave approximation. Standard p-shell wave functions, supplemented by renormalization factors deduced from electromagnetic and β-decay data, are used to describe the target nuclei in these calculations. Results obtained using a phenomenological 1 fm range Yukawa interaction illustrate the information on proton-neutron differences contained in the data for quadrupole transitions in 7Li and differences in the energy dependence of the spin-flip and non-spin-flip isovector central components of the effective interaction contained in the data for the (p, n) reaction on this same target. Results obtained with the more realistic G-matrix interaction of Bertsch et al. give a reasonable description of the overall features of the experimental data after 20–60 % reductions in the strengths of its varous components are made. The calculations fail to provide a consistent picture of the energy dependence of the optical potential and the quadrupole transition potentials. Some difficulties are also encountered in describing the cross sections for scattering to the 0 +, T = 1 level in the mass-6 systems.