156Gd基态SU(3)→O(6)相变的一种微观理解
Recognition of SU(3)→O(6) Quantum Phase Transition in Groundstates of 156Gd Nucleus within Microscopic Theory
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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6+1—8+1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 γray energy over spin curves identifies that there are the SU(3) and O(6) symmetries in the groundstates of the 156Gd nucleus; by means of the microscopic sdIBMmax approach and signalparticle experimental energies the spectra of those two symmetries and their transient process are successfully reproduced through two parameters of nucleonnucleon effective interaction with pairing plus quadrupole pairing plus quadrupolequadrupole forces. The calculated results reveal a new way to recognize groundstates quantum phase transition, in which the basicstate of the SU(3) symmetry is a lowlying and lowordered state, while one of the O(6) are a highlying and highordered state, their critical region is between 6+1—8+1 states, the highordered basicstate releases spare orderedstructure energy, reducing rotationspeed, thus causing the restructure of lowordered basicstate and accomplishing the quantum phase transition from the highordered phase into the lowordered phase, the shape phase transition takes place along the yrast line of nucleus when it deexcited to the critical region. Because the structural phase transition takes place by noobvious 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.
Abstract: The γray energy over spin curves identifies that there are the SU(3) and O(6) symmetries in the groundstates of the 156Gd nucleus; by means of the microscopic sdIBMmax approach and signalparticle experimental energies the spectra of those two symmetries and their transient process are successfully reproduced through two parameters of nucleonnucleon effective interaction with pairing plus quadrupole pairing plus quadrupolequadrupole forces. The calculated results reveal a new way to recognize groundstates quantum phase transition, in which the basicstate of the SU(3) symmetry is a lowlying and lowordered state, while one of the O(6) are a highlying and highordered state, their critical region is between 6+1—8+1 states, the highordered basicstate releases spare orderedstructure energy, reducing rotationspeed, thus causing the restructure of lowordered basicstate and accomplishing the quantum phase transition from the highordered phase into the lowordered phase, the shape phase transition takes place along the yrast line of nucleus when it deexcited to the critical region. Because the structural phase transition takes place by noobvious 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.