Exotic Deformations in Heavy Unstable Nuclei

重不稳定核中的奇异变形

• 批准号: 10640264
• 负责人: MATSUYANAGI Kenichi
• 金额: $ 0.77万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10640264/
• 关键词: 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

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

1.在三维Cartcian网格表象下，采用Cranked Skyrme-Hartree-Fock方法，在不加空间几何限制的情况下，研究了D132双稳D1 S的高自旋结构.结果表明：（1）在角动量I [相似或相等] 24处的yraast线上发生了从超形变到类超形变的交叉，这对应于曲柄谐振子模型中的“带终止”点，2）Y_（231）_13.2.我们构造了一个新的计算核结构的Cranked Skyrme-Hartree-Fock-Bogoliubov方法的计算机程序，它基于三维Cartesian网格表示，自洽地考虑了包括连续态在内的对关联。该方案的一个新特点是， ...更多信息 对称性是强加的。利用这个程序，我们研究了A=60-80区域的富质子N=Z核的奇异形状，发现了一个非轴向的八极（三角形）形状.本文用改进的定相法导出了二维椭圆台球能级密度的解析迹公式。其结果是变形参数（偏心率）通过短直径轨道及其重复的所有分叉点的连续函数，并具有正确的极限圆台球在零偏心率。远离循环极限和分支，它减少到通常的（扩展）Gutzwiller迹公式，其中的领导阶族的周期轨道是相同的Berry和塔博尔的结果。我们发现短直径和双曲轨道的共同分歧点附近的振幅增强。计算出的半经典能级密度和壳层能量与量子力学的结果符合得很好。少

项目成果

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A.G.Magner：“周期轨道理论中的对称破缺和分岔。I -椭圆台球-”Prog.Theor.Phys.. vol.102 No.3。

K.Arita: "Semiclassical Origin of Superdeformed Shell Structure in the Spheroidal Cavity Model"Progress of Theoretical Physics. 100. 1223-1238 (1998)

K.Arita：“球腔模型中超变形壳结构的半经典起源”理论物理进展。

A.G.Magner: "Symmetry Breaking and Bifurcations in the Periodic Orbit Theory.I-Elliptic Billicrd-"Progress of Theoretical Physics. 102. 551-598 (1999)

A.G.Magner：“周期轨道理论中的对称性破缺和分叉。I-椭圆Billicrd-”理论物理学进展。

M.Yamagami: "Exotic Shapes in ^<32>S suggested by the Symmetry-Unrestricted, Cranked Hartree-Fock Calculations"AIP Conference Proceedings. 481. 327-332 (1998)

M.Yamagami：“由对称无限制、曲柄Hartree-Fock 计算建议的^<32>S 中的奇异形状”AIP 会议记录。

M.Matsuo: "Adiabatic Selfconsistent Collective Coordinate Method for Large Amplitude Collective Motion in Nuclei with Pairing Correlations"Prog.Theor.Phys.. (印刷中). (2000)

M.Matsuo：“具有配对相关性的原子核大振幅集体运动的绝热自洽集体坐标方法”Prog.Theor.Phys..（出版中）。