Large-scale shell-model calculation with core excitations for neutron-rich nuclei beyond132Sn

Abstract

The structure of neutron-rich nuclei with a few nucleons beyond ${}^{132}$Sn is investigated by means of large-scale shell-model calculations. For a considerably large model space, including neutron core excitations, a new effective interaction is determined by employing the extended pairing-plus-quadrupole model with monopole corrections. The model provides a systematical description for energy levels of $A=133$--135 nuclei up to high spins and reproduces available data of electromagnetic transitions. The structure of these nuclei is analyzed in detail, with emphasis of effects associated with core excitations. The results show evidence of hexadecupole correlation in addition to octupole correlation in this mass region. The suggested feature of magnetic rotation in ${}^{135}$Te occurs in the present shell-model calculation.