Study of nuclear deformation by boson models

用玻色子模型研究核变形

基本信息

批准号：
01540231
负责人：
OTSUKA Takaharu
金额：
$ 1.6万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1991
项目状态：
已结题

项目摘要

The following points have been clarified in this research project. (1) The phase transition between spherical and deformed shapes is studied in terms of the sdg boson model, by taking Samarium isotopes. It has been indicated that the phase transition produces a clear effect on M1 excitation strength. This kind of studies have been extended to Polonium, Radium, etc. It has been shown what Pauli effect should appear in E2 transition strength throughout this phase transition. (2) Octupole deformation has been studied in terms of the spdf boson model. (3) Triaxial deformation has been investigated in terms of the sd boson model. The relation between level compression and gamma unstable deformation was studied with analytic expressions for O(6) symmetry.Besides these studies, the structure of odd mass nuclei has been studied in terms of the Interacting Boson-Fermion Model. The moment of inertia of high-spin states has been studied with a simple expression for its variation for even-even nuclei. Superdeformation has been described by introducing an extended model of the Interacting Boson Model. The E2 decay out of superdeformed bands was suggested. Mixed-symmetry states have been invesigated for Ion, Cadmium and Barium isotopes. The relations between chaos and symmetries have been studied in terms of the shell model and the boson model. The nuclear rotation has been discussed from the viewpoint of quantal coupling of proton and neutron bodies.Thus, various aspects of the nuclear collective motion have been studied, providing us with deeper understandings.

本研究项目明确了以下几点。 (1) 采用钐同位素，根据 sdg 玻色子模型研究球形和变形形状之间的相变。研究表明，相变对M1激发强度产生明显的影响。此类研究已扩展到钋、镭等。已经表明在整个相变过程中，E2 相变强度应出现何种泡利效应。 (2)根据spdf玻色子模型研究了八极变形。 (3) 根据sd玻色子模型研究了三轴变形。利用O(6)对称性的解析表达式研究了能级压缩与伽玛不稳定变形之间的关系。除了这些研究之外，还根据相互作用玻色子-费米子模型研究了奇质量核的结构。已经用一个简单的表达式研究了高自旋态的惯性矩对于偶偶核的变化。通过引入相互作用玻色子模型的扩展模型来描述超变形。建议 E2 从超变形带中衰减。离子、镉和钡同位素的混合对称态已被研究。根据壳模型和玻色子模型研究了混沌与对称性之间的关系。从质子和中子体量子耦合的角度讨论了核旋转，从而对核集体运动的各个方面进行了研究，为我们提供了更深入的理解。