Angular distributions for the ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}(\alpha ,\mathrm{t}){}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ and ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}(\alpha ,\mathrm{h}){}_{}{}^{28}{}_{}{}^{}\mathrm{Al}$ one-nucleon transfer reactions have been measured for an incident energy of 80 MeV. Finite-range distorted-wave Born-approximation calculations, using new $\mathrm{sd}$-shell model wave functions, were found to be in reasonable agreement with the data corresponding to exciting positive-parity final states. Transitions to negative-parity $4^{-}$, $5^{-}$, and $6^{-}$ $T=0\mathrm{} \mathrm{and} 1$ states display shapes characteristic of an $l=3\mathrm{}$ orbital angular momentum transfer, consistent with a dominant ($0f_{\frac{7}{2}}0d_{\frac{5}{2}}^{-1\mathrm{}}$) model configuration. Extracted strengths are in generally fair agreement with previous results, except for those corresponding to the unbound $5^{-}$ and $6^{-}$ $T=1\mathrm{}$ ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ states which are about 50% more fragmented than previously observed.

• Received 27 December 1983

DOI:https://doi.org/10.1103/PhysRevC.29.2017