Cejnar P, Jolie J
Institute of Particle and Nuclear Physics, Charles University, V Holesovickach 2, 180 00 Prague, Czech Republic.
Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 2000 Jun;61(6 Pt A):6237-47. doi: 10.1103/physreve.61.6237.
We study quasicritical phenomena in transitions between two "quantum phases" of a finite boson system, described by the interacting boson model 1 used in nuclear physics. The model is formulated in the algebraic framework and has a simple geometrical interpretation; the "phases" represented by dynamical symmetries U(5) and SU(3) correspond to spherical and deformed nuclear shapes. The quasicriticality of the U(5)-SU(3) transition is shown to be connected with the following phenomena simultaneously occurring in a narrow parameter region between the symmetries: (a) abrupt structural changes of eigenstates, (b) multiple avoided crossing of levels, (c) peaked density of exceptional points, (d) qualitative changes of the corresponding classical potential. We show that these spectroscopic features influence the dynamics of intersymmetry transitions in the model parameter space if the parameters themselves become dynamical variables.
我们研究了有限玻色子系统在两个“量子相”之间转变过程中的准临界现象，该系统由核物理中使用的相互作用玻色子模型1描述。该模型在代数框架中构建，具有简单的几何解释；由动力学对称性U(5)和SU(3)表示的“相”分别对应于球形和变形核形状。U(5) - SU(3)转变的准临界性被证明与在对称性之间的狭窄参数区域中同时出现的以下现象有关：(a)本征态的突然结构变化，(b)能级的多次避免交叉，(c)例外点的峰值密度，(d)相应经典势的定性变化。我们表明，如果参数本身成为动力学变量，这些光谱特征会影响模型参数空间中对称性间转变的动力学。
