Microscopic analysis of octupole shape transitions in neutron-rich actinides with relativistic energy density functional

Abstract

Quadrupole and octupole deformation energy surfaces, low-energy excitation spectra, and electric transition rates in eight neutron-rich isotopic chains -- Ra, Th, U, Pu, Cm, Cf, Fm, and No -- are systematically analyzed using a quadrupole-octupole collective Hamiltonian model, with parameters determined by constrained reflection-asymmetric and axially-symmetric relativistic mean-field calculations based on the PC-PK1 energy density functional. The theoretical results of low-lying negative-parity bands, odd-even staggering, average octupole deformations $⟨{\beta }_3⟩$, and $B(E3;3_1^{-}\to 0_1^{+})$ show evidence of a shape transition from nearly spherical to stable octupole-deformed, and finally octupole-soft equilibrium shapes in the neutron-rich actinides. A microscopic mechanism for the onset of stable octupole deformation is also discussed in terms of the evolution of single-nucleon orbitals with deformation.

arXiv comment13 pages, 10 figures, Accepted for Publication in Chinese Physics C. arXiv admin note: substantial text overlap with arXiv:1710.08230; text overlap with arXiv:1402.6102 by other authors

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Cited by in corpus (13)

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• Evolution of octupole deformation and collectivity in neutron-rich lanthanides
• Octupole correlations in light actinides from the interacting boson model based on the Gogny energy density functional
• Quadrupole-octupole coupling and the onset of octupole deformation in actinides
• Microscopic core-quasiparticle coupling model for spectroscopy of odd-mass nuclei with octupole correlations
• Microscopic origin of reflection-asymmetric nuclear shapes
• Microscopic description of quadrupole-octupole coupling in neutron-rich actinides and superheavy nuclei with the Gogny-D1M energy density functional
• Microscopic description of octupole collective excitations near $N=56$ and $N=88$
• Microscopic description of quadrupole-octupole coupling in actinides with the Gogny-D1M energy density functional
• Coupling of shape and pairing vibrations in a collective Hamiltonian based on nuclear energy density functionals
• Quadrupole-octupole coupling and the evolution of collectivity in neutron-deficient Xe, Ba, Ce, and Nd isotopes
• Non-relativistic expansion of single-nucleon Dirac equation: Comparison between Foldy-Wouthuysen transformation and similarity renormalization group