复动量表象方法对奇特核中晕现象的研究

Study on Halo Phenomenon in Exotic Nuclei by Complex Momentum Representation Method

晕现象的研究使人们对核结构有了新的认识。连续谱,尤其是连续谱中的共振态在其中扮演着重要角色。复动量表象(CMR)方法不仅能够统一描述束缚态、共振态和连续谱,而且能够很好地描述窄共振和宽共振。本文介绍了CMR方法对原子核共振态的研究。给出了^(31)Ne和^(19)C等核的束缚态和共振态的单粒子能量随形变参数β_(2)的变化规律,分析了^(19)C和^(31)Ne中单中子晕形成的物理机制和在中子数N=20附近能级反转的原因,并预测了比^(37)Mg重的核中的单中子晕现象,这一预测结果对在实验中寻找较重的晕核具有一定的参考价值。这些研究表明CMR方法不仅适用于描述稳定核,也适用于描述具有弥散物质分布的奇特核。

The study of halo phenomenon gives us a new understanding of nuclear structure,in which the continuum,especially the resonance in the continuum,plays an important role.The complex momentum representation(CMR) method can not only describe the bound state,resonant state and continuous spectrum uniformly,but also describe the narrow and wide resonance well.In this paper,the CMR method is introduced for the study of nuclear resonance.The single particle energy of bound state and resonance state of ^(31)Ne and ^(19)C with deformation parameter β_(2) is given.The physical mechanism of halo formation in ^(19)C and ^(31)Ne and the reason of energy level inversion near the neutron number N=20 are analyzed.The halo phenomenon in nuclei heavier than ^(37)Mg is predicted.The result of this prediction is helpful to find heavier halo nuclei in experiments.These studies show that the CMR method is suitable for describing not only stable nuclei,but also exotic nuclei with diffuse material distribution.