Microscopic calculations of C2 and C4 form factors in sd-shell nuclei Original Research Article

Inelastic electron scattering to 2+ and 4+ states for the even–even N=Zsd-shell nuclei (20Ne, 24Mg, 28Si and 32S) are discussed taking into account higher energy configurations outside the sd-shell. Higher energy configurations, which are called core polarization effects, are included through a microscopic theory that includes excitations from the core 1s and 1p orbits and also from 2s–1d shell to the higher allowed orbits with 2ℏω excitations. The predictions of C2 and C4 Coulomb form factors are compared with the available experimental data. The calculations based on the Wildenthal interaction for the sd-shell model space and on the modified surface delta interaction for the core-polarization effects. The effect of higher excited configurations is found essential in both the transition strength and momentum transfer dependence of form factors, and gives a remarkably good agreement with the measured data.