Multiparticle-octupole coupling and magnetic moments of h 9 2n isomers in N = 126 isotones

Abstract

The influence of particle-vibration coupling on the g-factors of the |(h 9 2)n〉 isomers in the N = 126 isotones is assessed using the multiparticle-octupole-coupling model. According to the model, admixtures of the configuration |(h 9 2)n-1f 7 2〉 in the yrast 8+ and 21 2- states, nominally associated with the configuration |(h 9 2)n〉, increase with n. On its own, the octupole mixing mechanism therefore predicts g-factors for these states that increase with the number of valence protons. This trend is the opposite of that predicted by core-polarization blocking. Combining multiparticle-octupole coupling and first-order core-polarization blocking significantly reduces the discrepancy between the experimental and theoretical g-factors of these states. We conclude that the observed breakdown in additivity for the g-factors of the |(h 9 2n)〉 isomers in the N = 126 isotones arises primarily from first-order core-polarization blocking and the combination of configuration mixing due to multiparticle-octupole coupling and shell-model residual interactions. Show more