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.

arXiv comment12 pages, 12 figures

References in corpus (32)

• Relativistic Nuclear Energy Density Functionals: adjusting parameters to binding energies
• New effective interactions in RMF theory with non-linear terms and density-dependent meson-nucleon coupling
• Global systematics of octupole excitations in even-even nuclei
• Mean field and beyond description of nuclear structure with the Gogny force: A review
• Direct Evidence of Octupole Deformation in Neutron-Rich ${}^{144}$Ba
• Cluster Interpretation of Properties of Alternating Parity Bands in Heavy Nuclei
• Octupole deformation in the ground states of even-even nuclei: a global analysis within the covariant density functional theory
• Microscopic description of octupole shape-phase transitions in light actinides and rare-earth nuclei
• Direct Evidence for Octupole Deformation in ${}^{146}$Ba and the Origin of Large $E1$ Moment Variations in Reflection-Asymmetric Nuclei
• Fission properties for r-process nuclei
• Evolution of Octupole Deformation in Radium Nuclei from Coulomb Excitation of Radioactive ${}^{222}$Ra and ${}^{228}$Ra Beams
• Landscape of pear-shaped even-even nuclei
• Analytic Description of Critical Point Actinides in a Transition from Octupole Deformation to Octupole Vibrations
• Microscopic analysis of the octupole phase transition in Th isotopes
• Robust Regularity in γ-Soft Nuclei and its Microscopic Realization
• Quadrupole shape invariants in the interacting boson model
• Spectroscopy of quadrupole and octupole states in rare-earth nuclei from a Gogny force
• Microscopic description of quadrupole-octupole coupling in Sm and Gd isotopes with the Gogny Energy Density Functional
• Octupole deformation properties of the Barcelona-Catania-Paris energy density functionals
• First direct measurement of the intrinsic dipole moment in pear-shaped thorium isotopes
• Spectroscopy of reflection-asymmetric nuclei with relativistic energy density functionals
• Octupole deformation in the nuclear chart based on the 3D Skyrme Hartree-Fock plus BCS model
• Octupole deformation in the ground states of even-even $Z\sim 96,N\sim 196$ actinides and superheavy nuclei
• Octupole deformation properties of actinide isotopes within a mean field approach
• Ground state octupole correlation energies with effective forces
• Parameter-Free Solution of the Bohr Hamiltonian for Actinides Critical in the Octupole Mode
• Microscopic description of fission in superheavy nuclei with the parametrization D1M${}^{\ast }$ of the Gogny energy density functional
• Octupole correlations in light actinides from the interacting boson model based on the Gogny energy density functional
• High-resolution $(p,t)$ study of low-spin states in ${}^{240}$Pu: Octupole excitations, $\alpha$ clustering, and other structure features
• Microscopic description of quadrupole-octupole coupling in actinides with the Gogny-D1M energy density functional
• Microscopic analysis of octupole shape transitions in neutron-rich actinides with relativistic 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