2026/07/29 by Dae Ik Kim, Masaaki Kimura, Chang-Hwan Lee +1
Physics and Astronomy · #nucl-th
6 pages, 3 figures
arxiv created 2026/07/29 · arxiv updated 2026/07/30
To clarify the mirror energy differences (MEDs) of the proton-unbound nucleus 29Cl and their microscopic origins, we investigate the low-lying states of the 29Cl-29Mg mirror pair using antisymmetrized molecular dynamics. The calculation reasonably reproduces the normal and intruder states of 29Mg, while suggesting alternative spin-parity assignments for 29Cl. The 1/2+ and 3/2+ states are predicted to form a nearly degenerate ground-state doublet with a small MED because of their similar intrinsic structures. In contrast, the 3/2- and 7/2- intruder states exhibit large negative MEDs and are assigned to the observed resonances at approximately 500~keV and 1.1~MeV, respectively. Their large MEDs originate from the reduced Coulomb energies associated with the stronger deformation and spatially extended proton distributions in the intruder configurations.