Effect of configuration mixing on quadrupole and octupole collective states of transitional nuclei

Abstract

A model is presented that simultaneously describes shape coexistence and quadrupole and octupole collective excitations within a theoretical framework based on the nuclear density functional theory and the interacting boson model. An optimal interacting-boson Hamiltonian that incorporates the configuration mixing between normal and intruder states, as well as the octupole degrees of freedom, is identified by means of self-consistent mean-field calculations using a universal energy density functional and a pairing interaction, with constraints on the triaxial quadrupole and the axially-symmetric quadrupole and octupole shape degrees of freedom. An illustrative application to the transitional nuclei ${}^{72}$Ge, ${}^{74}$Se, ${}^{74}$Kr, and ${}^{76}$Kr shows that the inclusion of the intruder states and the configuration mixing significantly lower the energy levels of the excited $0^{+}$ states, and that the predicted low-lying positive-parity states are characterized by the strong admixture of nearly spherical, weakly deformed oblate, and strongly deformed prolate shapes. The low-lying negative-parity states are shown to be dominated by the deformed intruder configurations.

14 pages, 8 figures, 4 tables

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Cited by in corpus (6)

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• Mapped interacting boson model for nuclear structure studies
• Effects of pairing strength on the nuclear structure and double-$\beta$ decay predictions within the mapped interacting boson model
• Role of octupole shape degree of freedom in neutron-rich odd-mass xenon isotopes
• Weakening of $N=28$ shell gap and the nature of $0_2^{+}$ states
• Octupole correlation effects on two-neutron transfer intensity in rare-earth nuclei