Quadrupole-hexadecapole coupling in the rare earth region with beyond mean field correlations

Abstract

The roles of static hexadecapole deformation and beyond-mean-field quadrupole-hexadecapole configuration mixing are studied for a selected set of Yb, Hf, W and Os isotopes within the mass range $170\le A\le 202$, using the Hartree-Fock-Bogoliubov (HFB) and the two-dimensional Generator Coordinate Method (2D-GCM) approaches, based on the Gogny energy density functional. The 2D-GCM ground and excited states of the lighter isotopes are associated with diamond-like shapes while, for each isotopic chain, a region where those states correspond to square-like shapes has been found below the neutron shell closure $N=126$. It is shown, that for the studied nuclei the quadrupole and hexadecapole degrees of freedom are interwoven in the ground and excited states up to the mass number $A=184-188$. This structural evolution, encoded in the 2D-GCM collective wave functions, is accompanied by an enhanced prolate-oblate shape coexistence around the neutron number $N=116$. In agreement with previous studies, it is also shown that for the considered Yb, Hf, W and Os isotopes the inclusion of hexadecapole deformation in the ground state dynamics leads to a non trivial additional correlation energy comparable to the quadrupole correlation energy itself.

12 pages, 7 figures. arXiv admin note: text overlap with arXiv:2502.04985

References in corpus (20)

• Status and Future of Nuclear Matrix Elements for Neutrinoless Double-Beta Decay: A Review
• Beyond the relativistic mean-field approximation (III): collective Hamiltonian in five dimensions
• Role of triaxiality in the ground state shape of neutron rich Yb, Hf, W, Os, and Pt isotopes
• Shape transitions in neutron-rich Yb, Hf, W, Os, and Pt isotopes within a Skyrme Hartree-Fock + BCS approach
• Spectroscopy of quadrupole and octupole states in rare-earth nuclei from a Gogny force
• Evidence of Hexadecapole Deformation in Uranium-238 at the Relativistic Heavy Ion Collider
• Skyrme-Hartree-Fock-Bogoliubov mass models on a 3D Mesh: Effect of triaxial shape
• 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
• Microscopic description of fission in superheavy nuclei with the parametrization D1M${}^{\ast }$ of the Gogny energy density functional
• Microscopic description of fission in odd-mass uranium and plutonium nuclei with the Gogny energy density functional
• Microscopic description of quadrupole-octupole coupling in neutron-rich actinides and superheavy nuclei with the Gogny-D1M energy density functional
• Microscopic description of quadrupole-octupole coupling in actinides with the Gogny-D1M energy density functional
• Hexadecapole strength in the rare isotopes ${}^{74,76}$Kr
• Operator overlaps in harmonic oscillator bases with different oscillator lengths
• Formulation of the Generator Coordinate Method with arbitrary bases
• Beyond-mean-field description of octupolarity in dysprosium isotopes with the Gogny-D1M energy density functional
• Quadrupole-hexadecapole correlations in neutron-rich samarium and gadolinium isotopes
• Microscopic description of quadrupole-hexadecapole coupling in radium, thorium, uranium and plutonium isotopes with the Gogny energy density functional

Cited by in corpus (1)

• Impacts of hexadecapole correlations in actinide nuclei