Speaker
Description
Intruder configurations can strongly influence mirror energy differences (MEDs) in nuclei near the island of inversion. We study the 29Mg-29Cl mirror pair using antisymmetrized molecular dynamics (AMD), focusing on how intruder configurations affect the MEDs. The calculated spectrum describes both normal and intruder configurations in 29Mg and leads to new spin-parity assignments for the low-lying resonances of proton-unbound 29Cl. A clear contrast is found between the positive- and negative-parity states: the 1/2+ and 3/2+ states show relatively small MEDs, whereas the intruder 3/2- and 7/2- states undergo substantial energy lowering in 29Cl. Analysis of the Coulomb contribution shows that this behavior is associated with enhanced deformation and extended proton distributions of the intruder states, which reduce their Coulomb energies.