We have used an ab initio Gamow shell model to study the isospin symmetry breaking in the $A=16$ mirror nuclei of ${}^{16}\mathrm{F}, {}^{16}\mathrm{N}, {}^{16}\mathrm{Ne}$, and ${}^{16}\mathrm{C}$. Starting from a chiral interaction with two-nucleon force (2NF) at ${\mathrm{N}}^3\mathrm{LO}$ and three-nucleon force (3NF) at ${\mathrm{N}}^2\mathrm{LO}$, a complex-momentum psd-shell Hamiltonian was constructed by employing the many-body perturbation theory in the Gamow Hartree-Fock basis which includes bound, resonant, and continuum states self-consistently. Such an elaborated ab initio Gamow shell model with both continuum coupling and 3NF included can properly treat the many-body correlations of weakly bound and unbound nuclei. The mirror partners of ${}^{16}\mathrm{F}$ and ${}^{16}\mathrm{N}$ exhibit different level orders in their excitation spectra, which can be well explained by the inclusion of 3NF in the calculation. The isospin asymmetry between the mirror partners ${}^{16}\mathrm{Ne}$ and ${}^{16}\mathrm{C}$ was studied in detail by insight into their configuration structures. The interplay between 3NF and the continuum coupling is discussed in the weakly bound and unbound nuclear states.

• Received 19 December 2022
• Accepted 8 December 2023

DOI:https://doi.org/10.1103/PhysRevC.108.064316