Hyperheavy spherical and toroidal nuclei: The role of shell structure

Journal Article · Thu Mar 25 00:00:00 EDT 2021 · Physical Review C

DOI:https://doi.org/10.1103/physrevc.103.034323· OSTI ID:1785283

Agbemava, S. E. ^[1]; Afanasjev, A. V. ^[2]

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1. Mississippi State Univ., Mississippi State, MS (United States); Ghana Atomic Energy Commission, Legon (Ghana); Mississippi State University
2. Mississippi State Univ., Mississippi State, MS (United States)

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 ≈ 130–180 region of the nuclear chart are established for the first time. These nuclei are stable with respect to breathing deformations. The most compact fat toroidal nuclei are located in the Z ≈ 136, N ≈ 206 region of the nuclear chart, but thin toroidal nuclei become dominant with increasing proton number and toward proton and neutron drip lines. The roles of toroidal shell structure, its regularity, supershell structure, and 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 a 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. Furthermore, the study suggests that the N = 210 toroidal shell gap plays a substantial role in the stabilization of fat toroidal nuclei.

• Research Organization: Mississippi State Univ., Mississippi State, MS (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• Grant/Contract Number: SC0013037
• OSTI ID: 1785283
• Journal Information: Physical Review C, Journal Name: Physical Review C Journal Issue: 3 Vol. 103; ISSN 2469-9985
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
Nuclear charge distribution
Nuclear density functional theory
Nuclear many-body theory
Nuclear structure & decays