Interplay between the freedoms of intrisic deformations and tilting angles of rotation-axis at high-spin states of atomic nuclei

原子核高自旋态下固有变形自由度与旋转轴倾斜角之间的相互作用

• 批准号: 12640281
• 负责人: SHIMIZU Yoshihumi
• 金额: $ 1.47万
• 依托单位: KYUSHU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12640281/
• 关键词: rapidly rotating nuclei; shape coexistence; superdeformed states; cranking model; tilted axis cranking; collective coordinate; collective mass tensor

The main purpose of this research work is to study the interplay between the deformation and rotation degrees of freedom by using the collective coordinate method. Especially, the interplay between the quadrupole deformation and the tilting of rotation-axis is expected to be important for the understanding the nuclear structure of rapidly rotating nuclei from a microscopic viewpoint.In these two year's of research, we have accomplished several important achievements, but still there are some parts which remains to be finished. The final goal to calculate the collective wave function in high accuracy by solving the basic equation of the collective coordinate method is under investigation; especially, there is still a difficulty to perform the calculation in the case to treat the rotational degrees of freedom selfconsistently. Here we summarize what we have achieved: l) A efficient and high-speed method to calculate the RPA correlation energy, and using this method it becomes possible to … More obtain a good realistic potential energy surface. 2) As a effective interaction, the quadrupole pairing force is extremely important for rotational degrees of freedom. We have developed a method to construct the diabatic quasiparticle basis including this force, and it is proved to be very useful for the calculation of rotational potential energy. 3) By utilizing the dynamic tunneling method to the deformation degrees of freedom, we have developed a general theoretical framework to treat the decay of the high-spin isomers and of the superdeformed rotational bands, and found that the framework can be applicable to many realistic situations. 4) As for the tilting degrees of freedom for the rotation-axis, the tilted axis cranking method within the mean-field treatment is very useful as a zero-order approximation, and as an example, we have found that it is able to describe the one-quasiparticle strongly-coupled rotational band in realistic nuclei. 5) In the case that the rotation-axis does not deviate very much from the principal-axis of deformation, we have checked that the RPA treatment of tilting axis can be applicable to investigate the recently observed nuclear wobbling motion excited on the triaxial superdeformed rotational band from a microscopic viewpoint. Less

这项研究工作的主要目的是利用集体坐标方法研究变形和旋转自由度之间的相互作用。尤其是四极变形与旋转轴倾斜之间的相互作用，对于从微观角度理解快速旋转核的核结构具有重要意义。在这两年的研究中，我们已经取得了一些重要的成果，但仍有一些部分有待完成。通过求解集体坐标法基本方程，高精度计算集体波函数的最终目标正在研究中；特别是在处理旋转自由度自洽的情况下，计算仍然存在困难。这里我们总结一下我们取得的成果： l) 一种高效、高速的 RPA 相关能计算方法，使用该方法可以获得良好的真实势能面。 2）作为一种有效的相互作用，四极配对力对于旋转自由度极其重要。我们开发了一种构建包含该力的非绝热准粒子基础的方法，并且它被证明对于旋转势能的计算非常有用。 3）通过利用变形自由度的动态隧道方法，我们开发了一个通用的理论框架来处理高自旋异构体和超变形旋转能带的衰变，并发现该框架可以适用于许多实际情况。 4）对于旋转轴的倾斜自由度，平均场处理中的倾斜轴曲柄方法作为零阶近似非常有用，作为一个例子，我们发现它能够描述现实原子核中的单准粒子强耦合旋转带。 5）在旋转轴与变形主轴偏离不是很大的情况下，我们已经验证了倾斜轴的RPA处理可以适用于从微观角度研究最近观察到的在三轴超变形旋转带上激发的核摆动运动。较少的

项目成果

M. Matsuzaki, Y. R. Shimizu, and K. Matsuyanagi: "Wobbling Motion in Atomic Nucli with Positive-Gamma Shapes"Physical Review C. (in press). (2002)

M. Matsuzaki、Y. R. Shimizu 和 K. Matsuyanagi：“具有正伽马形状的原子核中的摆动运动”物理评论 C.（出版中）。

K.Yoshida, M.Matsuo, Y.R.Shimizu: "Barrier Penetration and Rotational Damping of Thermally Excited Superdeformed Nuclei"Nuclear Physics. A696(1-2December). 85-122 (2001)

K.Yoshida、M.Matsuo、Y.R.Shimizu：“热激发超变形核的势垒穿透和旋转阻尼”核物理。

P.Donati, at all: "Effective Nucleon Mass iii Deformed Nuclei"Physical Review Letter. Vol.84No.19. 4317-4320 (2000)

P.Donati，完全：“有效核子质量 iii 变形核”物理评论信。

Y.R.Shimizu, K.Matsuyanagi: "Diabatic Mean-field Description of Rotational Bands in Terms of the Selfconsistent Collective Coordinate Method"Progress of Theoretical Physics Supplement. 141, April. 285-327 (2001)

Y.R.Shimizu、K.Matsuyanagi：“根据自洽集体坐标法对旋转能带的非绝热平均场描述”理论物理进展增刊。

Y.R.Shimizu: "On the Response Function Technique for Calculating the Random-Phase Approximation Correlation Energy"Physical Review Letter. 85・11. 2260-2263 (2000)

Y.R.Shimizu：“计算随机相位近似相关能量的响应函数技术”物理评论信 85・11 2260-2263（2000）。