Shell structure of superheavy nuclei in self-consistent mean-field models

Journal Article · Wed Sep 01 00:00:00 EDT 1999 · Physical Review, C

DOI:https://doi.org/10.1103/PhysRevC.60.034304· OSTI ID:6326178

Bender, M; Rutz, K; Maruhn, J A; Greiner, W ^[1]; Bender, M ^[2]; Bender, M ^[3]; Reinhard, P ^[4]; Reinhard, P; Maruhn, J A; Greiner, W ^[5]

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1. Institut fuer Theoretische Physik, Universitaet Frankfurt, Robert-Mayer-Strasse 10, D-60325 Frankfurt (Germany)
2. Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599-3255 (United States)
3. Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996 (United States)
4. Institut fuer Theoretische Physik II, Universitaet Erlangen-Nuernberg, Staudtstrasse 7, D-91058 Erlangen (Germany)
5. Joint Institute for Heavy-Ion Research, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831 (United States)

We study the extrapolation of nuclear shell structure to the region of superheavy nuclei in self-consistent mean-field models[emdash]the Skyrme-Hartree-Fock approach and the relativistic mean-field model[emdash]using a large number of parametrizations which give similar results for stable nuclei but differ in detail. Results obtained with the folded-Yukawa potential which is widely used in macroscopic-macroscopic models are shown for comparison. We focus on differences in the isospin dependence of the spin-orbit interaction and the effective mass between the models and their influence on single-particle spectra. The predictive power of the mean-field models concerning single-particle spectra is discussed for the examples of [sup 208]Pb and the spin-orbit splittings of selected neutron and proton levels in [sup 16]O, [sup 132]Sn, and [sup 208]Pb. While all relativistic models give a reasonable description of spin-orbit splittings, all Skyrme interactions show a wrong trend with mass number. The spin-orbit splitting of heavy nuclei might be overestimated by 40[percent][endash]80[percent], which exposes a fundamental deficiency of the current nonrelativistic models. In most cases the occurrence of spherical shell closures is found to be nucleon-number dependent. Spherical doubly magic superheavy nuclei are found at [sub 184][sup 298]114, [sub 172][sup 292]120, or [sub 184][sup 310]126 depending on the parametrization. The Z=114 proton shell closure, which is related to a large spin-orbit splitting of proton 2f states, is predicted only by forces which by far overestimate the proton spin-orbit splitting in [sup 208]Pb. The Z=120 and N=172 shell closures predicted by the relativistic models and some Skyrme interactions are found to be related to a central depression of the nuclear density distribution. This effect cannot appear in macroscopic-microscopic models or semiclassical approaches like the extended Thomas-Fermi-Strutinski integral approach which have a limited freedom for the density distribution only. In summary, our findings give a strong argument for [sub 172][sup 292]120 to be the next spherical doubly magic superheavy nucleus. [copyright] [ital 1999] [ital The American Physical Society]

• OSTI ID: 6326178
• Journal Information: Physical Review, C, Vol. 60:3; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
HEAVY NUCLEI
LEAD 208
MEAN-FIELD THEORY
NUCLEAR POTENTIAL
NUCLEAR STRUCTURE
OXYGEN 16
SHELL MODELS
SKYRME POTENTIAL
TIN 132
YUKAWA POTENTIAL
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
EVEN-EVEN NUCLEI
INTERMEDIATE MASS NUCLEI
ISOTOPES
LEAD ISOTOPES
LIGHT NUCLEI
MATHEMATICAL MODELS
MINUTES LIVING RADIOISOTOPES
NUCLEAR MODELS
NUCLEI
NUCLEON-NUCLEON POTENTIAL
OXYGEN ISOTOPES
POTENTIALS
RADIOISOTOPES
SECONDS LIVING RADIOISOTOPES
STABLE ISOTOPES
TIN ISOTOPES
663110* - General & Average Properties of Nuclei & Nuclear Energy Levels- (1992-)
663120 - Nuclear Structure Models & Methods- (1992-)