Ab initio calculations of isomers in nuclei near the magic number N=50

The study of nuclear isomers can deepen our understanding of nuclear structure and astrophysics. In this work, we have performed the Ab initio calculations of the isomers in the N =49 isotones. With a chiral two- plus three-nucleon force, the valence-space effective Hamiltonian was derived using the Ab initio many-body perturbation theory named Q-box folded diagrams. The effective operators of electromagnetic operators and β-decay were obtained using Θ-box folded diagrams. With the effective Hamiltonian and operators, we studied the properties of the isomers, gaining a microscopic understanding of the single-particle behaviour of the isomers which we are interested in, showing the reliability of the Ab initio calculations.