Quadrupole-octupole coupling and the onset of octupole deformation in actinides

Abstract

The evolution of quadrupole and octupole collectivity and their coupling is investigated in a series of even-even isotopes of the actinide Ra, Th, U, Pu, Cm, and Cf with neutron number in the interval $130⩽N⩽150$. The Hartree-Fock-Bogoliubov approximation, based on the parametrization D1M of the Gogny energy density functional, is employed to generate potential energy surfaces depending upon the axially-symmetric quadrupole and octupole shape degrees of freedom. The mean-field energy surface is then mapped onto the expectation value of the $sdf$ interacting-boson-model Hamiltonian in the boson condensate state as to determine the strength parameters of the boson Hamiltonian. Spectroscopic properties related to the octupole degree of freedom are produced by diagonalizing the mapped Hamiltonian. Calculated low-energy negative-parity spectra, $B(E3;3_1^{-}\to 0_1^{+})$ reduced transition rates, and effective octupole deformation suggest that the transition from nearly spherical to stable octupole-deformed, and to octupole vibrational states occurs systematically in the actinide region.

12 pages, 12 figures

References in corpus (12)

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• Ground state octupole correlation energies with effective forces
• Microscopic description of fission in superheavy nuclei with the parametrization D1M${}^{\ast }$ of the Gogny energy density functional
• Microscopic description of quadrupole-octupole coupling in actinides with the Gogny-D1M energy density functional
• Pairing vibrations in the interacting boson model based on density functional theory

Cited by in corpus (10)

• Evolution of octupole deformation and collectivity in neutron-rich lanthanides
• Quadrupole-octupole coupling and the evolution of collectivity in neutron-deficient Xe, Ba, Ce, and Nd isotopes
• Octupole correlations in collective excitations of neutron-rich $N\approx 56$ nuclei
• Origin of octupole deformation softness in atomic nuclei
• Beyond-mean-field description of octupolarity in dysprosium isotopes with the Gogny-D1M energy density functional
• Mapped interacting boson model for nuclear structure studies
• Microscopic description of quadrupole-hexadecapole coupling in radium, thorium, uranium and plutonium isotopes with the Gogny energy density functional
• Quadrupole-hexadecapole correlations in neutron-rich samarium and gadolinium isotopes
• Simultaneous description of $\beta$ decay and low-lying structure of neutron-rich even- and odd-mass Rh and Pd nuclei
• Impacts of hexadecapole correlations in actinide nuclei