Macro-microscopic Nuclear Mass Model Based On Covariant Density Functional

In the past few decades,the theoretical research of nuclear mass models has made great progress,and the description of known region of nuclear mass has been greatly improved.However,the results predicted by the theory for different mass models have obvious differences when extrapolated to the neutron-rich nuclei of far away from the known region.Therefore,the establishment of accurate and reliable nuclear mass model is of great significance to for understanding of nuclear mass.In this paper,the single-particle spectra in relativistic Hartree-Fock（RHF）theory are employed to extract shell correction energies with the Strutinsky method,and the importance of the proper box sizes R_box used in RHF calculation to extract reliable shell correction energies has been investigated.Based on the obtained shell correction energy and two macroscopic droplet models,a macro-microscopic nuclear mass model based on covariant density functional has been established.The prediction accuracy of the new mass model is investigated and discussed by comparing with the theoretical results of the RHF and experimental data.The main research achievements are as follows:1.The shell correction energies are extracted by Strutinsky method based on the RHF theory.An empirical formula to determine R_box is proposed by systematic studies on nuclei over a wide range of nuclear charts,including light,heavy,neutron-deficient,and neutron-rich nuclei,and their uncertainties of the shell correction energies due to the uncertainty of R_box are investigated as well.It is found that the results extracted by the Strutinsky method can be used to evaluate the nuclear shell structure information.The reliability of this empirical formula is further verified by the systematic calculation of O、Ca、Ni、Sn、Pb isotopes and N=50 isotones,and the shell correction energies of these nuclei are extracted based on the proper R_box.2.Combining the two macroscopic droplet models with the microscopic correction energy of RHF theory extracted by Strutinsky shell correction method,a macro-microscopic nuclear mass model based on covariant functional has been constructed.The results show that this macro-microscopic nuclear mass model is in good agreement with the experimental data of nuclear mass and has higher accuracy than RHF theory for the medium-heavy nuclei.