Ab initio descriptions of $A=16$ mirror nuclei with resonance and continuum coupling

Abstract

We have used an {\it ab initio} Gamow shell model to study the isospin symmetry breaking in the $A=16$ mirror nuclei of ${}^{16}$F, ${}^{16}$N, ${}^{16}$Ne and ${}^{16}$C. Starting from a chiral interaction with two-nucleon force (2NF) at N${}^3$LO and three-nucleon force (3NF) at N${}^2$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 {\it 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 ${}^{16}$F and ${}^{16}$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 ${}^{16}$Ne and ${}^{16}$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.

Comments: 7 pages, 4 figures