A coherent microscopic picture for the exotic structure of 11Be

The neutron-rich nucleus 11 Be is one of the most enigmatic exotic nuclei in the periodic table. It exhibits a multitude of unique and intriguing phenomena within a single nucleus, including the halo phenomenon, clustering structure, and parity inversion. A unified description of these exotic properties represents a significant challenge for the nuclear physics field. By employing the axially deformed relativistic Hartree-Fock-Bogoliubov (D-RHFB) model, we have successfully reproduced the parity inversion and the one-neutron halo in 11 Be, and revealed the underlying cluster structure. It is found that the intrusion of the sd -shell, which results in the parity inversion, is coherently connected with the halo and cluster structures. In particular, the s -wave is responsible for the halo formation, and the mixing of 2 s 1 / 2 - and 1 d 5 / 2 -waves enhances the cluster structure. This work elucidates the coherence between the parity inversion and the halo/cluster structures of 11 Be, and addresses the long-standing challenge of providing a unified explanation for the multiple exotic phenomena observed in 11 Be.