48Si: An atypical nucleus?

• Published in: Physics letters. B Vol. 788; pp. 192 - 197
• Main Authors: Li, Jia Jie, Long, Wen Hui, Margueron, Jérôme, Van Giai, Nguyen
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2019; Elsevier
• Subjects: Bubble-like structure; Drip-line nucleus; New magicity; Pairing reentrance; Drip-line nucleus; Pairing reentrance; New magicity; Bubble-like structure
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/j.physletb.2018.11.034

Using the relativistic Hartree–Fock Lagrangian PKA1, we investigate the properties of the exotic nucleus 48Si, which is predicted to be an atypical nucleus characterized by i) the onset of doubly magicity, ii) its location at the drip line, iii) the presence of dual semi-bubble structure (distinct central depletion in both of neutron and proton density profiles) in the ground state, and iv) the occurrence of pairing reentrance at finite temperature. While not being new for each, these phenomena are found to simultaneously occur in 48Si. For instance, the dual semi-bubble structure reduces the spin–orbit splitting of low-ℓ orbitals and upraises the s orbitals, leading therefore to distinct N=34 and Z=14 magic shells in 48Si. Consequently, the doubly magicities provide extra stability for such extreme neutron-rich system at the drip line. Associating with the neutron shell N=34 and continuum above, the pairing correlations are reengaged interestingly at finite temperature. Theoretical nuclear modelings are known to be poorly predictive in general, and we asset our confidence in the prediction of our modeling on the fact that the predictions of PKA1 in various regions of the nuclear chart have systematically been found correct and more specifically in the region of pf shell. Whether our predictions are confirmed or not, 48Si provides a concrete benchmark for the understanding of the nature of nuclear force.