Where is the(2s12)2T=1Strength in Mass 18?

A doublet at 4.5-MeV excitation energy in ${}_{}{}^{18}{}_{}{}^{}\mathrm{Ne}$ has been studied via the reactions ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}({}_{}{}^3{}_{}{}^{}\mathrm{He},n){}_{}{}^{18}{}_{}{}^{}\mathrm{Ne}$ and ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}\mathrm{}(p,t)\mathrm{}{}_{}{}^{18}{}_{}{}^{}\mathrm{Ne}$. The states are found to have excitation energies of 4.518±0.008 and 4.590±0.008 MeV with spin and parity $1^{-}$ and $0^{+}$, respectively. The difference between the excitation energy of the $0^{+}$ state and that of the analogous state at 5.34 MeV in ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$ gives strong evidence for the predominantly $s_{\frac{1}{2}}^{}{}_{}{}^2$ character of the state.