复动量表象方法对丰中子Cr 同位素奇特结构的研究  

Study on the Exotic Structures of the Neutron-rich Cr Isotopes by the Complex Momentum Representation Method

作　　者：曹雪能 郭建友[2] Xueneng CAO;Jianyou GUO(School of Management Science and Engineering,Anhui University of Finance and Economics,Bengbu 233030,Anhui,China;School of Physics and Optoelectronics and Engineering,Anhui University,Hefei 230601,China)

机构地区：[1]安徽财经大学管理科学与工程学院,安徽蚌埠233030 [2]安徽大学物理与光电工程学院,合肥230601

出　　处：《原子核物理评论》2023年第1期17-24,共8页Nuclear Physics Review

基　　金：国家自然科学基金资助项目(12205001,11935001);安徽财经大学科研项目(ACKYC22080)。

摘　　要：奇特核的研究是核物理中最有趣的前沿课题之一。中等质量核中是否存在晕现象,目前的研究相对较少。复动量表象(CMR)方法可以用来探索原子核中的奇特结构。连续谱阈值附近的共振态在奇特现象的形成中起着重要的作用。利用相对论点耦合框架下的复动量表象(RMFPC-CMR)方法研究了丰中子Cr同位素中的奇特结构,得到的非常接近于零的双中子分离能和迅速增大的中子均方根半径表明在靠近中子滴线的Cr同位素中存在晕结构。从获得的单粒子能级、费米面附近价核子占据几率、中子和质子密度分布以及各能级对原子核密度的贡献可以发现3s1/2和2d3/2能级的占据有利于中子晕的形成。研究发现,低角动量弱束缚能级对异常增大的半径和弥散密度分布有显著的贡献,这导致靠近中子滴线的76-82Cr是中子晕核。这一预测结果对在实验中探索中等质量区的晕核具有一定的参考价值。The study of exotic nuclei is one of the most interesting frontier topics in nuclear physics.There are relatively few studies on the existence of halo in medium-mass nuclei.The complex momentum representation(CMR)method can be used to explore exotic structures in nuclei.The resonant states near the continuum threshold play an important role in the formation of exotic phenomena.Therefore,the relativistic point coupled and the complex momentum representation(RMFPC-CMR)method is used to explore the exotic structures for the neutron-rich Cr isotopes.The two-neutron separation energies have been calculated to be very close to zero,and the mean square(rms)radii of neutron also have increased sharply,implying the presence of halo structures in the Cr isotopes near the neutron drip line.The single-particle levels,the occupation probabilities of valence nucleons on the levels near the Fermi surface,the neutron and proton density distributions,and the contribution of every level to the nucleus density are obtained,it can be found that the occupations of the levels 3s1/2 and 2d3/2 are beneficial to the formation of neutron halo.It is found that the unusual increases of rms radii and diffuse distributions of neutron densities come mainly from the contributions of the weakly bound levels with lower orbital angular momentum,which leads to the neutron halos of 76-82Cr near the neutron drip line.This prediction has a certain reference value for exploring the halo nuclei in the medium mass region in experiments.

关 键 词：相对论点耦合模型 复动量表象方法 单粒子能级 晕 

分 类 号：O571.2[理学—粒子物理与原子核物理]