Hyperheavy spherical and toroidal nuclei: the role of shell structure

Abstract

The properties of toroidal hyperheavy even-even nuclei and the role of toroidal shell structure are extensively studied within covariant density functional theory. The general trends in the evolution of toroidal shapes in the $Z\approx 130-180$ region of nuclear chart are established for the first time. These nuclei are stable with respect of breathing deformations. The most compact fat toroidal nuclei are located in the $Z\approx 136,N\approx 206$ region of nuclear chart, but thin toroidal nuclei become dominant with increasing proton number and on moving towards proton and neutron drip lines. The role of toroidal shell structure, its regularity, supershell structure, shell gaps as well as the role of different groups of the pairs of the orbitals in its formation are investigated in detail. The lowest in energy solutions at axial symmetry are characterized either by large shell gaps or low density of the single-particle states in the vicinity of the Fermi level in at least one of the subsystems (proton or neutron). Related quantum shell effects are expected to act against the instabilities in breathing and sausage deformations for these subsystems. The investigation with large set of covariant energy density functionals reveals that substantial proton $Z=154$ and 186 and neutron $N=228$, 308 and 406 spherical shell gaps exist in all functionals. The nuclei in the vicinity of the combination of these particle numbers form the islands of stability of spherical hyperheavy nuclei. The study suggests that the $N=210$ toroidal shell gap plays a substantial role in the stabilization of fat toroidal nuclei.

arXiv comment25 pages, 19 figures, submitted to Physical Review C, revised version with suggestions of referee taken into account

References in corpus (38)

• A New Parameterization for the Lagrangian Density of Relativistic Mean Field Theory
• Neutron-Rich Nuclei in Heaven and Earth
• New parametrization for the nuclear covariant energy density functional with point-coupling interaction
• Relativistic Nuclear Energy Density Functionals: adjusting parameters to binding energies
• The effective force NL3 revisited
• A finite range pairing force for density functional theory in superfluid nuclei
• Nuclear Ground State Observables and QCD Scaling in a Refined Relativistic Point Coupling Model
• Global performance of covariant energy density functionals: ground state observables of even-even nuclei and the estimate of theoretical uncertainties
• Relativistic mean field interaction with density dependent meson-nucleon vertices based on microscopical calculations
• Potential Energy Surfaces of Actinide Nuclei from a Multi-dimensional Constraint Covariant Density Functional Theory: Barrier Heights and Saddle Point Shapes
• Multidimensionally-constrained relativistic mean field models and potential energy surfaces of actinide nuclei
• Cranked Relativistic Hartree-Bogoliubov Theory: probing the gateway to superheavy nuclei
• Fission barriers in covariant density functional theory: extrapolation to superheavy nuclei
• Octupole deformation in the ground states of even-even nuclei: a global analysis within the covariant density functional theory
• The fission barriers in Actinides and superheavy nuclei in covariant density functional theory
• Covariant density functional theory: Reexamining the structure of superheavy nuclei
• Pairing and rotational properties of actinides and superheavy nuclei in covariant density functional theory
• Covariant energy density functionals: nuclear matter constraints and global ground state properties
• Global study of beyond-mean-field correlation energies in covariant energy density functional theory using a collective Hamiltonian method
• Deformed two center shell model
• Relativistic Energy Density Functional Description of Shape Transition in Superheavy Nuclei
• Properties of nuclei in the nobelium region studied within the covariant, Skyrme, and Gogny energy density functionals
• Assessing theoretical uncertainties in fission barriers of superheavy nuclei
• Description of rotating $N=Z$ nuclei in terms of isovector pairing
• Solving Dirac equations on a 3D lattice with inverse Hamiltonian and spectral methods
• Hyperheavy nuclei: existence and stability
• Stability of the linear chain structure for ${}^{12}$C in covariant density functional theory on a 3D lattice
• Extension of nuclear landscape to hyperheavy nuclei
• A region of high-spin toroidal isomers
• Evidence for high excitation energy resonances in the 7 alpha disassembly of ${}^{28}$Si
• High-spin torus isomers and their precession motions
• The shrinking instability of toroidal liquid droplets in the Stokes flow regime
• Toroidal high-spin isomers in the nucleus ${}^{304}120$
• Covariant density functional theory input for r-process simulations in actinides and superheavy nuclei: the ground state and fission properties
• Toroidal high-spin isomers in light nuclei with N not equal to Z
• Superheavy toroidal nuclei in the Skyrme energy functional framework
• Shells in a Toroidal Nucleus in the Intermediate Mass Region
• Exploring nuclear exotica at the limits

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