Unnatural parity transitions inNe22(p, t)Ne20

New measurements have been made with the ${}_{}{}^{22}{}_{}{}^{}\mathrm{Ne}(p, t)$ reaction to excite the $K^{\pi }=2^{-}$ rotational band in ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$. Coupled-channel Born approximation calculations fail to account for the angular distribution of the transition to the $4^{-}$ member of this band, although they describe well that for the transition to the $2^{-}$ member. Particularly significant is the failure of the cross section for the $4^{-}$ transition to decrease at forward angles. This behavior is in dis-agreement with that expected for unnatural parity transitions in ($p, t$) reactions which proceed through multistep processes involving inelastic excitations. The implications of these results for the reaction mechanism are discussed.