从核结构的有序性理解^(180,182)Hf核形状演化

Recognition of Shape Evolution of ^(180,182)Hf Nuclei From Order of Nuclear Structure

对于发生在同1个原子核中的从一种高激发模式向着低激发模式演化的物理图像,给出了一种新的理解:被布居到高角动量态的高有序激发核,以E2跃迁的方式先行退耦到转晕带,再退耦到共存区(或临界点)时释放了有序的结构能,诱发价核子对耦合强度改变,重新组合出低有序的激发模式基准态,实现了基准态结构的过渡;从微观上看,这是一种既温和而又平稳的转变。这种共存区(或临界点)在不同核素中位置的改变,就是研究基态量子相变的理论基础。文章阐述了连续发生两次这类相变的可能,并以180,182Hf核为例作了深入探讨。

A new standpoint is proposed for understanding the quantum phase transition from a higher-ordered excitation model to other lower-ordered one. It suggests that a nucleus populating at high-spin state is decoupled firstly to the yrast-band with the E2-trasitions mode, and then to the coexist region, wherein the structure-energy is released, the change of the nucleon coupling intensity is caused, finally the ground-states of the lower-ordered excitation model is reconstructed, the evolution of ground- state structure occurs. Microscopically, this is a benignancy and calm transition. In addition, an explanation is given to the possibility that two phase transitions can occur in some isotopes. A detailed discussion is presented with the 180,182^Hf nuclei as an example.