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

本研究的主要目的是利用集体坐标法研究变形自由度与旋转自由度之间的相互作用。特别是，四极变形和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，我们取得了一些重要的成果，但仍有一些有待完成的部分。通过求解集体坐标法的基本方程，实现高精度计算集体波函数的最终目标；特别是在自洽处理旋转自由度的情况下，计算仍然存在困难。本文总结了本文的研究成果：1)提出了一种高效、快速的计算RPA相关能的方法，并利用该方法获得了较好的真实势能面。2)四极配对力作为一种有效的相互作用，对转动自由度的影响是极其重要的。我们提出了一种包含这种力的非绝热准粒子基的构造方法，并证明了它对旋转势能的计算是非常有用的。3)通过对变形自由度的动态隧穿方法，我们建立了一个处理高自旋同分异构体和超变形旋转带衰变的一般理论框架，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，平均场处理下的倾斜轴曲柄法作为一种零阶近似是非常有用的，并作为一个例子，我们发现它能够描述现实核中单准粒子强耦合的旋转带。5)在旋转轴与变形主轴偏差不大的情况下，我们验证了倾斜轴的RPA处理可以从微观角度研究最近观测到的在三轴超变形旋转带上激发的核摆动运动。少

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