Isospin splitting of the Dirac mass probed using the relativistic Brueckner-Hartree-Fock theory  

作　　者：Pianpian Qin Qiang Zhao Hui Tong Chencan Wang Sibo Wang 

机构地区：[1]Department of Physics and Chongqing Key Laboratory for Strongly Coupled Physics,Chongqing University,Chongqing 401331,China [2]Center for Exotic Nuclear Studies,Institute for Basic Science,Daejeon 34126,Korea [3]Helmholtz-Institut für Strahlen-und Kernphysik and Bethe Center for Theoretical Physics,Universität Bonn,Bonn D-53115,Germany [4]School of Physics and Astronomy,Sun Yat-Sen University,Zhuhai 519082,China

出　　处：《Nuclear Science and Techniques》2025年第2期123-130,共8页核技术(英文)

基　　金：supported in part by the China Postdoctoral Science Foundation under grant No.2021M700610;the National Natural Science Foundation of China(NSFC)(No.12205030);the Fundamental Research Funds for the Central Universities(No.2024CDJXY022);the Institute for Basic Science(No.IBS-R031-D1).

摘　　要：The isospin splitting of the Dirac mass obtained using the relativistic Brueckner-Hartree-Fock(RBHF)theory was thor-oughly investigated.From the perspective in the full Dirac space,the long-standing controversy between the momentum-independent approximation(MIA)method and the projection method on the isospin splitting of the Dirac mass in asymmetric nuclear matter was analyzed in detail.We found that the assumption procedure of the MIA method,which assumes that single-particle potentials are momentum independent,is not a sufficient condition that directly leads to the opposite sign of the isospin splitting of the Dirac mass,whereas the extraction procedure of the MIA method,which extracts single-particle potentials from single-particle potential energy,changes the sign.A formal expression of the Dirac mass was obtained by approximately solving a set of equations involved in the extraction procedure.The opposite isospin splitting of the Dirac mass was mainly caused by the extraction procedure,which forcibly assumed that the momentum dependence of the single-particle potential energy was in a quadratic form,in which the strength was solely determined by a constant scalar potential.Improved understanding of the isospin splitting of the Dirac mass from ab initio calculations could enhance our knowledge of neutron-rich systems,such as exotic nuclei and neutron stars.

关 键 词：Dirac mass Relativistic Brueckner-Hartree-Fock theory Single-particle potential Momentum dependence 

分 类 号：O57[理学—粒子物理与原子核物理]