Resonant structure of and the shell
Phys. Rev. C 112, 024321 – Published 22 August, 2025
DOI: https://doi.org/10.1103/vktj-1wkr
Abstract
The resonant structure of the proton-unbound nucleus has been studied via knockout reactions of a beam on a target. Three resonant states in are identified through the invariant-mass reconstruction of events, including the ground state with one-proton decay energy of 1.38(2) MeV. In comparison with the low-lying states in the mirror neutron-rich nucleus , the ground state and excited state with configurations in likely correspond to different proton seniorities, and 1, respectively, while the and states with configuration show obvious Thomas-Ehrman shifts. With the more-precise atomic mass of , the one-neutron separation energy is derived. Based on the systematics of the differences in experimental one-neutron separation energy in the isotopic chains from to 12, the shell effects at for proton-rich nuclei are discussed.