Shells, orbit bifurcations, and symmetry restorations in Fermi systems

Journal Article · Tue Nov 15 04:00:00 EST 2016 · Physics of Atomic Nuclei

DOI:https://doi.org/10.1134/S1063778816060181· OSTI ID:22612577

Koliesnik, M. V. ^[1]; Arita, K. ^[2]

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1. NASU, Institute for Nuclear Research (Ukraine)
2. Nagoya Institute of Technology, Department of Physics (Japan)

The periodic-orbit theory based on the improved stationary-phase method within the phase-space path integral approach is presented for the semiclassical description of the nuclear shell structure, concerning themain topics of the fruitful activity ofV.G. Soloviev. We apply this theory to study bifurcations and symmetry breaking phenomena in a radial power-law potential which is close to the realistic Woods–Saxon one up to about the Fermi energy. Using the realistic parametrization of nuclear shapes we explain the origin of the double-humped fission barrier and the asymmetry in the fission isomer shapes by the bifurcations of periodic orbits. The semiclassical origin of the oblate–prolate shape asymmetry and tetrahedral shapes is also suggested within the improved periodic-orbit approach. The enhancement of shell structures at some surface diffuseness and deformation parameters of such shapes are explained by existence of the simple local bifurcations and new non-local bridge-orbit bifurcations in integrable and partially integrable Fermi-systems. We obtained good agreement between the semiclassical and quantum shell-structure components of the level density and energy for several surface diffuseness and deformation parameters of the potentials, including their symmetry breaking and bifurcation values.

• OSTI ID: 22612577
• Journal Information: Physics of Atomic Nuclei, Journal Name: Physics of Atomic Nuclei Journal Issue: 6 Vol. 79; ISSN 1063-7788; ISSN PANUEO
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ASYMMETRY
ENERGY-LEVEL DENSITY
FERMI LEVEL
FISSION BARRIER
FISSION ISOMERS
ORBITS
PATH INTEGRALS
PERIODICITY
PHASE SPACE
SEMICLASSICAL APPROXIMATION
SYMMETRY BREAKING
WOODS-SAXON POTENTIAL