Low-multipolarity magnetic transitions in [sup 30]Si, [sup 32]S, and [sup 34]S studied by 180[degree] electron scattering

Low-multipolarity magnetic transitions of [sup 30]Si, [sup 32]S, and [sup 34]S were studied by 180[degree] inelastic electron scattering at low momentum transfers ([ital q][similar to]0.3--0.5 fm[sup [minus]1]). These measurements, made in the excitation energy region from 9 to 14 MeV, revealed several previous unreported levels. These are the first low-[ital q] results obtained by electron scattering for [sup 30]Si and [sup 34]S. Multipolarities and transition strengths for all the observed transitions were determined in a model-independent analysis. A large fragmentation of [ital M]1 strength is observed in the 4[ital N]+2 nuclei [sup 30]Si and [sup 34]S, while more strength is concentrated into fewer transitions in the self-conjugate nucleus [sup 32]S. The experimental [ital M]1 strength distributions are compared with configuration-mixing shell-model calculations. The sums of the transition strengths are in good agreement with recent shell-model calculations using an effective [ital M]1 operator.