摘要
超核物理研究为揭示重子-重子相互作用的核介质中特性以及理解原子核与中子星内部结构提供了关键信息。基于密度依赖的相对论Hartree-Fock(RHF)理论,拟合单Λ超核中超子分离能实验数据得到模型中ΛN有效相互作用。交换项的引入改变了超子道中有效核力的动力学平衡,导致不同于相对论平均场模型的介子-超子耦合强度,进而影响超子自旋-轨道劈裂的描述。考虑到模型中有效核力取值的不确定性,进一步研究了单Λ超核的粗块及单粒子性质对于超子耦合强度的依赖,探索约束其取值范围的可能方法。具体以_(Λ)^(16)O超核为例,通过改变同位旋标量道超子耦合强度,系统分析了超核能量泛函中核介质与交换项效应。结果显示,超子自旋-轨道劈裂、Dirac有效质量以及超核特征半径等与超子耦合强度比值可能存在一定的线性关联。因此,通过实验或理论对这些物理量做出约束,有望对核介质中超子相关的有效核力给出更强的限制。
The research in hypernuclear physics provides crucial information for uncovering the characteristics of baryon-baryon interactions in the nuclear medium and understanding the internal structure of atomic nuclei and neutron stars.Based on the density-dependent relativistic Hartree-Fock(RHF)theory,the AN effective interaction in the model is obtained by fitting experimental data of hyperon separation energies for single-A hypernuclei.The inclusion of the Fock term alters the dynamic equilibrium of the effective nuclear force in the hyperon channel,resulting in a meson-hyperon coupling strength that differs from the relativistic mean-field model and influences the description of hyperon spin-orbit splitting.Considering the uncertainty in the values of the effective nuclear force within the model,further research is conducted to explore the dependencc of hypernuclear bulk and single-particle properties on the hyperon coupling strength,aiming to identify possible ways to constrain its range of values.Taking the _(Λ)^(16)O hypernucleus as an example,the effects of the nuclear medium and Fock terms are systematically analyzed by adjusting the hyperon coupling strength in the isoscalar channel within the hypernuclear energy functional.The results suggest a possible linear relationship between the ratio of hyperon coupling strength and quantities such as hyperon spin-orbit splitting,Dirac effective mass,and hypernuclear characteristic radius.Therefore,by constraining these quantities through experimental or theoretical means,it is possible to impose stronger limitations on the effective nuclear force associated with hyperons in the nuclear medium.
作者
丁士缘
杨威
陈兆京
孙保元
DING Shiyuan;YANG Wei;CHEN Zhaojing;SUN Baoyuan(MOE Frontiers Science Center for Rare Isotopes,Lanzhou University,Lanzhou 730000,China;School of Nuclear Science and Technology,Lanzhou University,Lanzhou 730000,China)
出处
《原子核物理评论》
CAS
CSCD
北大核心
2024年第1期207-213,共7页
Nuclear Physics Review
基金
中央高校基本科研业务费专项资金(lzujbky-2022-sp02,lzujbky-2023-stlt01)
国家自然科学基金资助项目(11875152,12275111)
中国科学院战略性先导科技专项资助(XDB34000000)。
关键词
单Λ超核
超子-核子相互作用
协变密度泛函
交换项
single-A hypernuclei
hyperon-nucleon interaction
covariant density functional
Fock terms
