双Λ超核同位旋标量巨共振性质的相对论研究  

Isoscalar giant resonances of^(18)ΛΛO in relativistic approach

作　　者：温静 孙帅 曹李刚 张丰收[1,2,3] Wen Jing;Sun Shuai;Cao Li-Gang;Zhang Feng-Shou(Key Laboratory of Beam Technology of Ministry of Education,College of Nuclear Science and Technology,Beijing Normal University,Beijing 100875,China;Institute of Radiation Technology,Beijing Academy of Science and Technology,Beijing 100875,China;Center of Theoretical Nuclear Physics,National Laboratory of Heavy Ion Accelerator of Lanzhou,Lanzhou 730000,China)

机构地区：[1]北京师范大学核科学与技术学院,射线束技术教育部重点实验室,北京100875 [2]北京市科学技术研究院,辐射技术研究所,北京100875 [3]兰州重离子加速器国家实验室,原子核理论研究中心,兰州730000

出　　处：《物理学报》2024年第4期105-112,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12275025,11975096,12135004,11635003,11961141004);中央高校基本科研业务费专项资金(批准号:2020NTST06)资助的课题.

摘　　要：基于相对论平均场理论(RMF),采用TM1以及有效超子−核子和超子−超子相互作用,首先研究了^(16)O和^(18)ΛΛO的单粒子能级受超子的影响情况,发现超子的加入使得核子能级能量降低.其次基于相对论无规位相近似方法(RRPA),自洽地计算了^(16)O和^(18)ΛΛO同位旋标量巨单极和四极共振态.发现相比于16O各巨共振的响应函数,超核的响应函数会发生改变.研究表明:这种改变主要来自于超子的加入导致的核子单粒子能级的改变,以及超子粒子−空穴组态跃迁的贡献,而超子−超子剩余相互作用对单极和四极共振在低能区的响应函数的影响比较小,特别对高能区的响应函数基本没有影响.The interactions between hyperon-nucleon and hyperon-hyperon have been an important topic in strangeness nuclear physics,which play an important role in understanding the properties of hypernuclei and equation of state of strangeness nuclear matter.It is very difficult to perform a direct scattering experiment of the nucleon and hyperon because the short lifetime of the hyperon.Therefore,the hyperon-nucleon interaction and the hyperon-hyperon interaction have been mainly investigated experimentally byγspectroscopy of single-Λhypernuclei or double-Λhypernuclei.There are also many theoretical methods developed to describe the properties of hypernuclei.Most of these models focus mostly on the ground state properties of hypernuclei,and have given exciting results in producing the banding energy,the energy of single-particle levels,deformations,and other properties of hypernuclei.Only a few researches adopting Skyrme energy density functionals is devoted to the study of the collective excitation properties of hypernuclei.In present work,we have extended the relativistic mean field and relativistic random phase approximation theories to study the collective excitation properties of hypernuclei,and use the methods to study the isoscalar collective excited state properties of doubleΛhypernuclei.First,the effect ofΛhyperons on the single-particle energy of^(16)O and^(18)ΛΛO are discussed in the relativistic mean field theory,the calculations are performed within TM1 parameter set and related hyperon-nucleon interaction,and hyperon-hyperon interaction.We find that it gives a larger attractive effect on the s1/2 state of proton and neutron,while gives a weaker attractive effect on the state around Fermi surface.The self-consistent relativistic random phase approximation is used to study the collectively excited state properties of hypernucleus^(18)ΛΛO.The isoscalar giant monopole resonance and quadrupole resonance are calculated and analysed in detail,we pay more attention to the effect of the inclusion ofΛhyperon

关 键 词：双Λ超核 巨共振 相对论无规位相近似 

分 类 号：O571[理学—粒子物理与原子核物理]