摘要
γ射线能量自旋曲线指认156Gd核基态具有SU(3)和O(6)两种对称性。基于微观sdIBM-■max方案和单粒子能量实验值,用两组核子之间的对作用、四极对作用、四极-四极作用的等效强度参数,都很好地再现了这两种能谱及其演化过程。计算结果揭示出对基态相变的一种新理解:SU(3)的基准态是低激发-低有序态,而O(6)基准态则是高激发-高有序的,它们有临界区61+—81+态;当核退耦到临界区时,高有序基准态释放多余的有序结构能,导致低有序基准态重组,实现减速旋转驱动高有序核向着低有序核过渡的量子相变。最后用156Gd核的势能曲面作了直观说明。
The γ-ray energy over spin curves identifies that there are the SU（3） and O（6） symmetries in the ground-states of the 156Gd nucleus;by means of the microscopic sdIBM-F max approach and signal-particle experimental energies the spectra of those two symmetries and their transient process are successfully reproduced through two parameters of nucleon-nucleon effective interaction with pairing plus quadrupole pairing plus quadrupole-quadrupole forces.The calculated results reveal a new way to recognize ground-states quantum phase transition,in which the basic-state of the SU（3） symmetry is a low-lying and low-ordered state,while one of the O（6） are a high-lying and high-ordered state,their critical region is between 6＋1—8＋1 states,the high-ordered basic-state releases spare ordered-structure energy,reducing rotation-speed,thus causing the restructure of low-ordered basic-state and accomplishing the quantum phase transition from the high-ordered phase into the low-ordered phase,the shape phase transition takes place along the yrast line of nucleus when it de-excited to the critical region.Because the structural phase transition takes place by no-obvious charge of boson structure constants in the critical region it is a benignancy and calm transition with respect to its macroscopic behave.The potential energy surface of 156Gd nucleus has been illustrated to visualize.
出处
《原子核物理评论》
CAS
CSCD
北大核心
2010年第3期257-262,共6页
Nuclear Physics Review
基金
贵州省教育厅自然科学重点项目(2006318)
贵州省科学技术基金资助项目([2009]2071号)~~
