Researchers from the Institute of Modern Physics at the Chinese Academy of Sciences have made significant strides in understanding the nuclear structure of proton-rich nuclei, particularly the isotope Silicon-22 ($^{22}$Si). Their findings, published in the journal Physical Review Letters, shed light on the “double-magicity” of $^{22}$Si, a term used to describe nuclei with full proton and neutron shells, which are particularly stable.
The team, led by J. G. Li and including H. H. Li, S. Zhang, Y. M. Xing, and W. Zuo, utilized advanced ab initio calculations to investigate the properties of $^{22}$Si and its mirror nucleus, Oxygen-22 ($^{22}$O). Ab initio methods aim to solve the nuclear many-body problem starting from realistic interactions between nucleons, providing a more fundamental approach to nuclear structure studies.
The researchers focused on the excitation energy of the first excited state ($E(2_1^+)$), a key indicator of nuclear shell structure. Their calculations confirmed the double-magicity of $^{22}$O and revealed that $^{22}$Si also exhibits similar characteristics, albeit with a lower $E(2_1^+)$. This reduction is attributed to the Thomas-Ehrman shift, a phenomenon related to the occupation of specific nuclear orbitals.
To further validate their findings, the team calculated the mirror energy difference (MED) between $^{22}$Si/$^{22}$O, as well as other silicon and magnesium, neon pairs. The results aligned well with experimental data, reinforcing the conclusion that $^{22}$Si is a double-magic nucleus. Notably, the many-body configurations of the low-lying states of $^{22}$Si and $^{22}$O were found to be nearly identical, despite the differences in their $E(2_1^+)$ values.
The practical implications of this research for the energy sector are indirect but significant. Understanding nuclear structure is fundamental to various energy-related applications, including nuclear power generation, nuclear waste management, and nuclear medicine. The insights gained from this study contribute to the broader knowledge base of nuclear physics, which can inform the development of advanced nuclear technologies and strategies for sustainable energy production.
In summary, the researchers have provided compelling evidence that $^{22}$Si is a double-magic nucleus, similar to its mirror nucleus $^{22}$O. Their findings enhance our understanding of nuclear structure and have potential implications for the energy industry, particularly in the realm of nuclear technologies. The study was published in Physical Review Letters, a prestigious journal in the field of physics.
This article is based on research available at arXiv.