The ${}_{}{}^{26}{}_{}{}^{}\mathrm{Mg}({}_{}{}^3{}_{}{}^{}\mathrm{He},n){}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ reaction at $E_{{}_{}{}^3{}_{}{}^{}\mathrm{He}}=15\mathrm{}$ MeV has been studied. Relative strengths to excited states in ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ are determined from a distorted-wave Born-approximation analysis of the data. The ratios $\frac{S(0^{+}\to J^{\pi })}{S(0^{+}\to 0^{+})}$ for the lowest $J^{\pi }=2^{+},4^{+}$ states compare favorably with predictions based on pure ${\mathrm{SU}}_3$ symmetry. When compared with results from the ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}({}_{}{}^6{}_{}{}^{}\mathrm{Li},d){}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ a consistent picture for the structure of the 0.0 ($0^{+}$), 1.78 ($2^{+}$), 4.62 ($4^{+}$), 4.98 ($0^{+}$), and 6.69 ($0^{+}$) MeV levels in ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ is suggested.

NUCLEAR REACTIONS ${}_{}{}^{26}{}_{}{}^{}\mathrm{Mg}({}_{}{}^3{}_{}{}^{}\mathrm{He},n) E=15\mathrm{}$ MeV; measured $\sigma \left(\theta \right)$, ${\theta }_{\mathrm{lab}}=0\mathrm{}°-55\mathrm{}°$; extracted strength with DWBA, compared with ${\mathrm{SU}}_3$ predictions.

• Received 24 March 1976

DOI:https://doi.org/10.1103/PhysRevC.14.4