(Pseudo)Spin Symmetries In The Single-Particle Resonant State Of Atomic Nuclei

With the continuous progress of radioactive nuclear beam and the continuous improvement of detection experimental technology,more and more exotic nuclei have been found far from the stability line,and become one of the hot research fields of nuclear physics.In recent years,the study of single-particle resonant states has attracted great attentions due to the essential roles in the exotic nuclei.In exotic nuclei,the neutron or the proton Fermi surface is very close to the continuum threshold and the valence nucleons can be easily scattered to the single-particle resonant states in the continuum due to the pairing correlations and the couplings between the bound states and the continuum become very important.Symmetry of resonant states of single particles plays an important role in the study of atomic structure and has been widely discussed.In this paper,the relativistic mean field theory(RMF)in the framework of covariant density functional theory(CDFT)is used as a theoretical tool,and taking the Green's function(GF)method as the theoretical research method,the following works have been completed:(1)Taking as an example,the spin and pseudospin symmetries in the the single-particle resonant states are studied.Giving details of the single-particle resonant states(including the resonant energies and widths of the single-particle resonant states),and calculate the single-particle levels(including the bound states and the resonant states in the continuous spectrum)by Green's function(GF)method.On this basis,the corresponding spin partners and pseudospin partners in the single-particle resonance states are found.The splittings of the doublets with the same main quantum number increase with the angular momentum 7).yy comparing the energy splittings,width splittings and average energies of the partners,it is found that the energy splittings of the pseudospin partners become negative.Contrast the density distribution of the(pseudo)spin partners at the resonance energy,the similarity properties of the wave functions of the spin and pseudospin doublets still maintain in resonant states.(2)Taking as an example,the pseudospin symmetries with different WoodsSaxon potentials are studied.Giving details of the single-particle resonant states with different Woods-Saxon potentials by Green's function method.The energies and widths of the single-particle resonant states decreases with the parameters of the nuclear potential in a Woods-Saxon type increases(except for and);The energy and width splitting of the pseudospin partners are obviously dependent on the parameters of potentials;with the parameters of potentials increasing,there is the opposite sign of energy splitting.