Shell-model structure of exoticSb135

Abstract

Recent studies have provided new experimental information on the very neutron-rich nucleus $^{135}\mathrm{Sb}$. We have performed a shell-model calculation for this nucleus by using a realistic effective interaction derived from the CD-Bonn nucleon-nucleon potential. This gives a very good description of the observed properties of $^{135}\mathrm{Sb}$. We show that the anomalously low position of the first excited state, ${J}^{\ensuremath{\pi}}=5/{2}^{+}$, and the strongly hindered $M1$ transition to the ground state have their origin in the effective neutron-proton interaction.