Coulomb Energy Shifts in theA=18Nuclei

The energies of the lowest five $T=1\mathrm{}$ states in ${\mathrm{F}}^{18}$ and ${\mathrm{Ne}}^{18}$ are predicted on the basis of a calculation (a) using a realistic force tuned to fit the ${\mathrm{O}}^{18}$ members of the same multiplets and (b) including the known Coulomb interactions between protons. The nucleons are permitted to be in the $1d_{\frac{5}{2}}$ and $1s_{\frac{1}{2}}$ levels, the latter being described by Woods-Saxon wave functions. Particle-particle, hole-particle, and hole-hole corrections are included. Reasonable agreement with experiment is obtained for all but the excited $0^{+}$ multiplet. It is necessary to introduce a small (short ranges and attractive) charge-dependent force to explain the ${\mathrm{F}}^{18}$ data.