准粒子特征与奇奇核的能谱统计

用粒子转子理论模型计算奇奇核⁸⁴Y的能谱,通过分析能谱的最近邻能级间距分布函数和能谱刚性度的变化特点,研究了准粒子特征对奇奇核⁸⁴Y能谱统计特点的影响,发现奇奇核⁸⁴Y的能谱总体上接近混沌;在采用的理论模型中,准粒子特征通过反冲项和科氏力作用项影响能谱,同时能谱具有随着费米能和能隙参量的减小从接近混沌逐渐转变到接近规则的特点 关键词： 奇奇核 粒子转子模型 准粒子特征 能谱统计 NNS分布函数 能谱刚性度

QUASIPARTICLE FEATURES AND LEVEL STATISTICS OF ODD-ODD NUCLEUS

The energy levels of the odd-odd nucleus 84Y are calculated by using the axially symmetric rotor plus quasiparticles model.The two standard statistical tests of Random-Matrix Theory such as the distribution function p(s) of the nearest-neighbor level spacings (NNS) and the spectral rigidity Δ3 are used to explore the statistical properties of the energy levels.By analyzing the properties of p(s) and Δ3 under various conditions, we find that the quasiparticle features mainly affect the statistical properties of the odd-odd nucleus 84Y through the recoil term and the Coriolis force in this theoretical mode, and that the chaotic degree of the energy levels decreases with the decrease of the Fermi energy and the energy-gap parameters.The effect of the recoil term is small while the Coriolis force plays a major role in the spectral structure of 84Y.