Islands of shape coexistence from single-particle spectra in covariant density functional theory

Abstract

Using covariant density functional theory with the DDME2 functional and labeling single-particle energy orbitals by Nilsson quantum numbers, a search for particle-hole (p-h) excitations connected to the appearance of shape coexistence is performed for Z=38 to 84. Islands of shape coexistence are found near the magic numbers Z=82 and Z=50, restricted in regions around the relevant neutron midshells N=104 and N=66 respectively, in accordance to the well accepted p-h interpretation of shape coexistence in these regions, which we call neutron-induced shape coexistence, since the neutrons act as elevators creating holes in the proton orbitals. Similar but smaller islands of shape coexistence are found near N=90 and N=60, restricted in regions around the relevant proton midshells Z=66 and Z=39 respectively, related to p-h excitations across the 3-dimensional isotropic harmonic oscillator (3D-HO) magic numbers N=112 and N=70, which correspond to the beginning of the participation of the opposite parity orbitals 1i13/2 and 1h11/2 respectively to the onset of deformation. We call this case proton-induced shape coexistence, since the protons act as elevators creating holes in the neutron orbitals, thus offering a possible microscopic mechanism for the appearance of shape coexistence in these regions. In the region around N=40, Z=40, an island is located on which both neutron p-h excitations and proton p-h excitations are present.

21 pages, 17 figures

References in corpus (25)

• Relativistic Continuum Hartree Bogoliubov Theory for Ground State Properties of Exotic Nuclei
• Nuclear magic numbers: new features far from stability
• Hidden pseudospin and spin symmetries and their origins in atomic nuclei
• DIRHB -- a relativistic self-consistent mean-field framework for atomic nuclei
• Global performance of covariant energy density functionals: ground state observables of even-even nuclei and the estimate of theoretical uncertainties
• Beyond the relativistic mean-field approximation (III): collective Hamiltonian in five dimensions
• Microscopic description of nuclear quantum phase transitions
• Beyond the relativistic mean-field approximation (II): configuration mixing of mean-field wave functions projected on angular momentum and particle number
• Configuration mixing of angular-momentum projected triaxial relativistic mean-field wave functions. II. Microscopic analysis of low-lying states in magnesium isotopes
• Structural evolution in $A\approx 100$ nuclei within the mapped interacting boson model based on the Gogny energy density functional
• Landscape of pear-shaped even-even nuclei
• Analytic predictions for nuclear shapes, the prolate dominance and the prolate-oblate shape transition in the proxy-SU(3) model
• Proxy-SU(3) symmetry in heavy deformed nuclei
• Global study of beyond-mean-field correlation energies in covariant energy density functional theory using a collective Hamiltonian method
• Energy Density Functional analysis of shape evolution in N=28 isotones
• Structural evolution in Pt isotopes with the Interacting Boson Model Hamiltonian derived from the Gogny Energy Density Functional
• The islands of shape coexistence within the Elliott and the proxy-SU(3) Models
• Shape coexistence in Lead isotopes in the interacting boson model with Gogny energy density functional
• The subtle connection between shape coexistence and quantum phase transition. The Zr case
• Global analysis of quadrupole shape invariants based on covariant energy density functionals
• Proxy-SU(3) symmetry in the shell model basis
• Quadrupole Collective Dynamics from Energy Density Functionals: Collective Hamiltonian and the Interacting Boson Model
• Microscopic origin of shape coexistence in the N=90, Z=64 region
• Connecting the proxy-SU(3) symmetry to the shell model
• Unified picture of nucleon pairs playing leading roles in nuclear collectivity

Cited by in corpus (8)

• Shape coexistence in even-even nuclei: A theoretical overview
• The proxy-SU(3) symmetry in atomic nuclei
• Signatures for shape coexistence and shape/phase transitions in even-even nuclei
• Islands of shape coexistence: theoretical predictions and experimental evidence
• Shape transition and coexistence in Te isotopes studied with the quadrupole collective Hamiltonian based on a relativistic energy density functional
• Coulomb excitation of ${}^{124}$Te: Emerging collectivity and persisting seniority structure in the $6_1^{+}$ level
• The pervasiveness of shape coexistence in nuclear pair condensates
• Effects of shape coexistence and configuration mixing on low-lying states in tellurium isotopes