[Submitted on 17 Dec 2025]
Double-magicity of proton drip-line nucleus Si with \textit{ab initio} calculation
J.G. Li · H. H. Li · S. Zhang · Y. M. Xing · W. Zuo
New magic numbers have been discovered in the neutron-rich region of the nuclear chart. However, there has been a lack of research on proton-rich nuclei. O, the mirror nucleus of Si, is a double-magic nucleus bearing a high . Whether Si exhibits double-magic characters is an intriguing topic. To investigate this matter, we utilized \textit{ab initio} valence space in-medium similarity renormalization group for Si/O, and their nearby nuclei. Our \textit{ab initio} calculations provide good descriptions for the double magicity of O, as well as the shell evolution of and through . The computed indicate that the closure of sub-shell in proton-rich nuclei is weaker than the sub-shell closure in their mirror nuclei. Particularly, the calculated of Si is 800 keV lower than the one of O. To further explore the magicity of Si, the mirror energy difference (MED) of Si/Mg, Si/Ne, as well as Si/O are calculated. The results demonstrate that the calculated MEDs agree well with available experimental data, and the values of Si are all lower than their respective mirror nuclei due to the Thomas-Ehrman shift with large occupation. Moreover, our calculation provides that the many-body configurations of the low-lying state of Si/O are nearly identical despite the fact that the states bearing large MED. In conclusion, our \textit{ab initio} results suggest that Si is a double magic nucleus, similar to its mirror nucleus O, albeit with a lower .
- Comments:
- 6 Pages, 4 Figures
- Subjects:
- Nuclear Theory (nucl-th)
- arXiv:
- 2512.15097 [pdf]