Elastic magnetic electron scattering from 17O, 25Mg and 27Al Original Research Article

Elastic magnetic electron scattering form factors for the 5/2+ state of the stable odd-A nuclei, in the sd-shell (17O, 25Mg and 27Al) have been investigated in terms of the configuration mixing shell model, including core polarization effects. Core polarization effects are taken into consideration through excitations of nucleons from the 1s and 1p core orbits and also from the valence 2s1d shell orbits into higher shells, with 2ℏω excitations. Core polarization effects improve the agreement with the data in the region of momentum transfer where M1 and M3 multipoles are important. The higher momentum transfer data, where the M5 contribution is the dominant contribution, are less affected by core polarization. In this region, the data are well described if the valence orbital is given a size, which is smaller than that required, by the root mean square charge radius.