New Aspects of Nuclear Deformation

在这个研究计划中，我们从各种新的方面研究了核四极和八极形变，包括动态形变和静态形变。我们使用的理论工具是相互作用玻色子模型（IBM）。质量数为-130的Ba和Ba核的γ不稳定形变是已知的。我们特别研究了^ψ的结构<130>，以研究O（6）动力学对称性在这个核中的保持程度。由科隆组得到的数据非常清楚地表明了O（6）动力学对称性。O（6）动力学对称是一个完美的描述，但似乎是相当抽象的。大冢对它的结构有了新的解释。O（6）动力学对称性可以看作是从变形平衡态激发的声子。有了这个观点，就可以对γ不稳定核的结构有更直观的认识。从转动阻尼和宽度的角度研究了量子混沌。O（6）核的磁跃迁是强烈增强的，并对最近科隆小组的实验数据进行了分析。用相互作用玻色子-费米子模型2分析了科隆小组对奇A核的Ml激发数据。用相互作用玻色子-费米子模型2研究了^&lt;125，127&gt; π核，得到了很好的实验与计算符合。

In this research project, nuclear quadruple and octupole deformations have been studied from various new aspects, including both dynamical and static deformations. The theoretical tool we have used is the Interacting Boson Model (IBM). The gamma-unstable deformation is known for Xe and Ba nuclei with the mass number-130. We studied the structure of ^<130>Xe, in particular, in order to investigate to what extent the O(6) dynamical symmetry holds in this nucleus. The data taken by Koeln group indicates very clearly the O(6) dynamical symmetry properties. The O(6) dynamical symmetry is a perfect description, but appears to be rather abstract. Otsuka developed a new interpretation of its structure. The O(6) dynamical symmetry can be viewed as the phonon excitation from a deformed equilibrium. With this view, a more intuitive understanding of the structure of gamma-unstable nuclei can be obtained. The quantum chaos has been studied in terms of the rotational damping and the width. The magnetic transitions are enhanced anomalously in the O(6) nuclei, and data taken recently by the Koeln group have been analyzed. The Interacting Boson-Fermion Model - 2 has been used to analyze the Ml excitation data by the Koeln group for odd-A nuclei. The nuclei ^<125,127>Xe have been studied in terms of the Interacting Boson-Fermion Model - 2, and a good agreement between experiment and calculation has been obtained.