| Project/Area Number |
10640264
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
素粒子・核・宇宙線
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
MATSUYANAGI Kenichi Depeartment of Physics, Graduate School of sicence, Associate Professor, 大学院・理学研究科, 助教授 (70025451)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1999: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1998: ¥700,000 (Direct Cost: ¥700,000)
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| Keywords | Superdeformation / High-Spin State / Octupole Deformation / Exotic Deformation / Shell Structure / Unstable Nuclei / Cranking Model / Trace Formula / シエル構造 / 核構造 / 回転バンド / 周期軌道理論 |
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| Research Abstract |
1. High-spin yrast structure of ィイD132ィエD1 S was investigated by means of the cranked Skyrme-Hartree-Fock method in the three-dimensional Cartcsian-mesh representation without imposing restrictions on spatial symmetrics. The result suggests that 1) a crossover from the superdeformed to the hyperdeformed-like configurations takes place on the yrast line at angular momentum I 【similar or equal】 24, which corresponds to the "band termination" point in the cranked harmonic-oscillator model, and 2) non-axial octupole deformations of the YィイD231ィエD2 type play an important role in the yrast states in the range 5 【less than or equal】 I 【less than or equal】 13.
2. We have constructed a new computer program of Cranked Skyrme-Hartree-Fock-Bogoliubov method for nuclear structure calculation, which is based on 3D Cartesianmesh representation and which selfconsistently takes into account pairing correlations including continuum states. A new feature of this program is that no restrictions on spatial
… More
symmetries are imposed. With the use of this program, we have investigated exotic shapes in proton-rich N=Z nuclei in the A=60-80 region and found a non-axial octupole (triangular) shape in ィイD168ィエD1Se.
3. We have derived an analytical trace formula for the level density of the two-dimensional elliptic billiard using an improved stationary phase method. The result is a continuous function of the deformation parameter (eccentricity) through all bifurcation points of the short diameter orbit and its repetitions, and possesses the correct limit of the circular billiard at zero eccentricity. Away from the circular limit and the bifurcations, it reduces to the usual (extended) Gutzwiller trace formula which for the leading-order families of periodic orbits is identical to the result of Berry and Tabor. We find enhancement of the amplitudes near the common bifurcation points of both short-diameter and hyperbolic orbits. The calculated semiclassical level densities and shell energies are in good agreement with the quantum mechanical ones. Less
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