Ab initio valence-space in-medium similarity renormalization group calculations for neutron-rich P, Cl, and K isotopes* *Supported by the National Key R&D Program of China (2023YFA1606403), the National Natural Science Foundation of China (12205340, 12175281, 12347106, 12121005), the Natural Science Foundation of Gansu Province, China (22JR5RA123, 23JRRA614), the Strategic Priority Research Program of Chinese Academy of Sciences (XDB34000000), the Key Research

Abstract

Neutron-rich P, Cl, and K isotopes, particularly those with neutron numbers of approximately , have attracted extensive experimental and theoretical interest. We utilize the ab initio valence-space in-medium similarity renormalization group approach, based on chiral nucleon-nucleon and three-nucleon forces, to investigate the exotic properties of these isotopes. Systematic calculations of the low-lying spectra are performed. A key finding is the level inversion between and states in odd-A isotopes, attributed to the inversion of and single-particle states. The ab initio calculations, which incorporate the three-nucleon forces, correlate closely with existing experimental data. Further calculations of effective proton single-particle energies provide deeper insights into the shell evolution for and sub-shells. Our results indicate that the three-body force plays important roles in the shell evolution for and sub-shells with neutron numbers ranging from 20 to 28. Additionally, systematic ab initio calculations are conducted for the low-lying spectra of odd-odd nuclei. The results correspond with experimental data and provide new insights for future research into these isotopes up to and beyond the drip line.