Spherical, Axial, and Triaxial Symmetries in the Study of Halo Nuclei with Covariant Density Functional Theory

The halo phenomenon in exotic nuclei has long been an important frontier in nuclear physics research since its discovery in 1985. In parallel with the experimental progress in exploring halo nuclei, the covariant density functional theory has become one of the most successful tools for the microscopic study of halo nuclei. Based on spherical symmetry, the relativistic continuum Hartree-Bogoliubov theory describes the first halo nucleus Li-11 self-consistently and predicts the giant halo phenomenon. Based on axial symmetry, the deformed relativistic Hartree-Bogoliubov theory in continuum has predicted axially deformed halo nuclei Mg-42,Mg-44 and the shape decoupling effects therein. Based on triaxial symmetry, recently the triaxial relativistic Hartree-Bogoliubov theory in continuum has been developed and applied to explore halos in triaxially deformed nuclei. The theoretical frameworks of these models are presented, with the efficacy of exploiting symmetries highlighted. Selected applications to spherical, axially deformed, and triaxially deformed halo nuclei are introduced.

Automated summary

The halo phenomenon in exotic nuclei has been a major focus in nuclear physics research since it was discovered in 1985. The covariant density functional theory has proven to be an effective tool in understanding the microscopic properties of halo nuclei. This theory has been successfully applied to study both spherical and deformed halo nuclei, and recently, a triaxial version of the theory has been developed and applied to investigate halos in triaxially deformed nuclei.