Many-Particle Shell Model Calculation of Electromagnetic Transition Rates and Multipole Moments in A = 30−34 Nuclei

Abstract

Many-particle shell model wavefunctions are used to calculate magnetic dipole and electric quadrupole transition probabilities. This chapter discusses calculations performed for bare-nucleon factors and charges, for effective factors and charges obtained from a least-squares fit to experimental data, and for effective single-particle matrix elements obtained from an analogous fit. A more sensitive test of the wavefunctions is provided by electromagnetic transition rates and multi-pole moments. A striking difference between strong Ml and strong E2 transitions follows from the fact that the first stem mainly from one or a few large components of the wavefunctions, whereas the latter come from a more or less coherent sum of many small components. Because the model wavefunctions are obtained in a truncated shell model space and the two-body interaction is very schematic, it can be expected that effective electromagnetic operators are needed.