Coupled-channel calculations of electron scattering by samarium

Abstract

The coupled-channel method is considered in the context of relativistic hadron or lepton scattering by nonspherical dynamical nuclei. The program Zenith, which calculates electron-nucleus scattering via Coulomb and magnetic multipole potentials, is described and is applied in particular to the deformed samarium isotopes Sm152 and Sm154. Two- and three-level calculations for the ground state 0+ and the excited states 2+ and 4+ containing all relevant l=0, 2, and 4 Coulomb potentials are described. The elastic dispersion effect, arising mainly from coupling with the 2+ first excited state, and the dispersive effect on the 0+ → 2+ inelastic cross section, coming mainly from the diagonal l=2 scattering in the excited state, are appreciable at 105 MeV, the highest energy at which measurements have been made. The largest effect, however, is that on the 0+ → 4+ inelastic cross section arising from the sequential excitation 0+ → 2+ → 4+ via the l=2 potential. It has interesting small-angle behavior and becomes greater than 20% at the largest measured angles at 105 MeV. The dependence of some of these effects on energy and qeff is explored up to 250 MeV and 2 fm-1. NUCLEAR REACTIONS Sm152,4(e,e′) calculations, coupled channels, 50 MeV<E<250 MeV. Dispersive effects on elastic and inelastic cross sections. © 1974 The American Physical Society.