MULTIPARTICLE OCTUPOLE COUPLING AND MAGNETIC-MOMENTS OF H(9 2)(N) ISOMERS IN N = 126 ISOTONES/

The influence of particle-vibration coupling on the g-factors of the \ (h9/2)n] isomers in the N = 126 isotones is assessed using the multipa rticle-octupole-coupling model. According to the model, admixtures of the configuration \(h9/2)n-1f7/2] in the yeast 8+ and 21-/2 states, no minally associated with the configuration \(h9/2)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. Th is trend is the opposite of that predicted by core-polarization blocki ng. Combining multiparticle-octupole coupling and first-order core-pol arization blocking significantly reduces the discrepancy between the e xperimental and theoretical g-factors of these states. We conclude tha t the observed breakdown in additivity for the g-factors of the \(h9/2 )n] 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 inter actions.