A Systematic Study Of Low-lying States In Light Nuclei Within Multi-reference Covariant Density Functional Theory

Nuclear covariant density functional theory has achieved great successful in describing many physical phenomena in atomic nuclei throughout the nuclear chart in recent decades. In particular, the multi-reference covariant density functional theory with projections for symmetry restoration and generator coordinate method for configuration mixing has shown to be a powerful method for nuclear low-lying states.Light nuclei are of particular interest because they cover three traditional magic number of neutron N=8,20, and28in this region. Lots of phenomena have been found and attracted extensively attentions, such as the weakening and disappearance of traditional shell and emerging the new magic number, halo structure and possible existence of bubble structure and cluster structure. In this work, a systematic study of low-lying states in light nuclei within multi-reference covariant density functional theory has been carried out.i). Low-lying spectrum and anti-bubble effect of dynamical correlations in46Ar: The calculated low-lying states are in excellent agreement with available data. Our results suggest the weakening of the N=28shell in Ar. Even though an evident proton bubble structure is shown in the spherical state of46Ar, it eventually disappears after taking into account the effect of the dynamical correlations. Our results indicate that the existence of a proton bubble structure in Ar isotopes is unlikely,ii). A systematic study of ground and low-lying states in light nuclei within multi-reference covariant density functional theory:Potential energy curves, full dynamical correlation energy, density distribution, the excitation energy of first2+and4+states and the electric quadrupole transition strengths among them have been calculated. We found that (1) the full dynamical correlation energy of light nuclei is0-4.5MeV, mainly resulting from the rotational correction energy and dependent on the shell structure sensitively;(2) the validity of cranking formula for open shell nuclei is demonstrated;(3)34Si nucleus is the best candidate with the bubble structure in light nuclei region;(4) a good agreement with the experimental value is found for the excitation energy of21+state and B(E2:21+â†'O1+) value in almost all the nuclei.