Thomas-Ehrman shifts in nuclei around 16O and role of residual nuclear interaction

The asymmetry in the energy spectra between mirror nuclei (the Thomas-Ehrman shifts) around 16O is investigated from a phenomenological viewpoint. The recent data on proton-rich nuclei indicates that the residual nuclear interaction is reduced for the loosely bound s-orbit by as much as 30%, which originates in the broad radial distribution of the proton single-particle wave function.