Study On The Ground State Properties Of Nuclei With Strangeness

The research on nuclei with strangeness is one of hot topics in the field of nuclear physics.It is also significant for particle physics and astrophysics.Nuclear experimental facilities in the world,such as J-PARC,KEK,HIAF,and so on,are being carried out or planning experiments of nuclei with strangeness,which needs more theoretical information.The thesis is to study the ground-state properties of nuclei with strangeness in Skyrme-Hartree-Fock(SHF)model and BCS approach.On the one hand,the research is to provide theoretical information.On the other hand,it is to testify strange particle-nucleon(YN),strange particle-strange particle(YY)interaction,and the power to describe and predict the properties of the nuclei with strangeness.In the framework of SHF model combined with Skyrme-type or microcosmic YN,YY interaction,the pairing effects in multi-Λ hyperisotopes are studied by considering the ΛΛ residual interaction-pairing force.The isospin-dependent Skyrme-type ΛN interaction is obtained by analyzing the Λ removal energies of Λ hypernuclei.Experimental results for the s-state Ξ hypernucleus Ξ15C are analyzed.The Skyrme-type EN interaction is optimized,and the experimental dada of all known Ξ hypernuclei are reproduced.The impurity effects of K-meson are investigated with a Skyrme-type K-N interaction.The contents are as follows:The pairing effects in multi-A hyperisotopes are studied by considering theΛΛ residual interaction—pairing force.The 2A removal energies,pairing gaps of hyperons and pairing energies of spherical-SΛ40-SCa.-SΛ132-SSn,-SΛ208-SPb and deformed-SΛ24-SMg,-SΛ56-S Fe,-SΛ104-SZr hyperisotopes are studied in deformed SHF model employing a δ-type pairing force.For spherical multi-A hypernuclei,the magic numbers are-S=2,8,18,20,34,58,68,and 70,which are attributed to a Woods-Saxon-like hyperon potential and the negligible Λ spin-orbit forces.For the deformed hyperisotopes,more possible hyperon magic numbers-S=4,6,10,14,26,30,and 32 are found based on the analysis of the single-particle energy levels,and are all sensitive to the quadrupole deformation β2.Deformation leads to the disappearance of pairing effects.The pairing effects dependents on the s.p.level density around the Fermi surface.The isospin-dependent Skyrme-type AN interaction is obtained by analyzing the Λ removal energies of Λ hypernuclei.The microcosmic ΛN interaction considering isospin effects only improves the description of proton-rich mirror Λ hypernuclei,while the Skyrme-type AN interaction have not included the isospin effects and deformation effects.For the better description of the properties of Λ hypernuclei,the isospin parameters x0,y0 are introduced into the volume-energy terms of the Skyrmetype ΛN interaction SLL4 based on the deformed SHF model.The isospin-dependent Skyrme-type ΛN interaction is obtained by fitting the experimental data of the Λ removal energies of isospin-symmetric hypernuclei Λ5He,Λ7Li,Λ9Be,Λ11B,Λ13C and mirrorΛ hypernuclei pairs Λ8Li/Λ8Be,Λ9Li/Λ9B,Λ10Be/Λ10B,Λ12B/Λ12C.The Skyrme-type EN interaction is optimized,and the experimental dada of all known Ξ hypernuclei are reproduced.Recently,the s-state Ξ hypernucleus Ξ15C(14N+Ξ-)is observed firstly in E07 of J-PARK,E373 of KEK-PS experiment,and several experimental dada of Ξ removal energies are provided.New experimental data can’t be reproduced with the existing EN interaction.Therefore,the EN interaction is optimized by analyzing the experimental dada of s,p-state Ξ removal energies ofΞ15C based on SHF model and the Skyrme-type ΞN interaction.The KISO,IBUKI,KINKA,BNL-E885,BNL-E906,KEK-E224,and KEK-E176 data which are revelant to all known Ξ hypernuclei,i.e.Ξ15,Ξ12Be,Ξ13B,are reproduced with new EN interaction.The important role of deformation for reproducing Ξ removal energy of Ξ13B is pointed out.The impurity effects of K-meson are investigated with a Skyrme-type K-N interaction.To have a thorough knowledge of the ground-state properties of kaonic nuclei,the effects of an additional K-meson on deformation,binding energies,onenucleon removal energy and the highest-occupied nucleon single-particle levels of Be,O,Ne isotopes are investigated within SHF model combined with a Skyrme-type K-N interaction.The K-meson increases the binding energies of all nuclei,whereas it affects deformations only for light nuclei without shell closure.The different effects of Kmeson on neutron drip line(increased,decreased,unchanging)of Be,O,Ne isotopes depend on the highest-occupied neutron single-particle levels of nuclei near the drip line.Owing to the attractive K-N interaction,this is attributed to the effects of the Kmeson on nucleonic mean field and spin-orbit potential in different regions.