Spectroscopy of positive parity states inMg26andAl26via the (α,3He) and (α,t) reactions

The (α${,}^3$He) and (α,t) reactions on ${}_{}{}^{25}{}_{}{}^{}\mathrm{Mg}$ were measured at ${\mathit{E}}_{\mathrm{\alpha }}$=50 MeV. Cross sections obtained for 57 positive parity states in ${}_{}{}^{26}{}_{}{}^{}\mathrm{Mg}$ and ${}_{}{}^{26}{}_{}{}^{}\mathrm{Al}$ were analyzed within the framework of the exact-finite-range distorted-wave Born approximation and compared to the full s-d shell model predictions. Reasonable agreement between the experimental strengths and the theory was obtained for the low lying states. Deviations of factors of 2 or more were found for some high lying $2^{+}$, $3^{+}$, and $4^{+}$ states in ${}_{}{}^{26}{}_{}{}^{}\mathrm{Al}$ and especially for the $1_1^{+}$ state in ${}_{}{}^{26}{}_{}{}^{}\mathrm{Mg}$. The spectroscopic factors for the transitions to the analog states in ${}_{}{}^{26}{}_{}{}^{}\mathrm{Mg}$ and ${}_{}{}^{26}{}_{}{}^{}\mathrm{Al}$ were compared between these reactions. The same strength was obtained for the $6_1^{\mathrm{-}}$, T=1 state in ${}_{}{}^{26}{}_{}{}^{}\mathrm{Mg}$ and ${}_{}{}^{26}{}_{}{}^{}\mathrm{Al}$, whereas an enhancement of about 30% was observed for the $0_1^{+}$ and $3_1^{+}$, T=1 states in ${}_{}{}^{26}{}_{}{}^{}\mathrm{Al}$. Further, $1^{+}$ states in ${}_{}{}^{26}{}_{}{}^{}\mathrm{Mg}$ proposed around ${\mathit{E}}_{\mathit{x}}$=10 MeV through the (p,p’) reaction were also observed in the ${}_{}{}^{25}{}_{}{}^{}\mathrm{Mg}$(α${,}^3$He) reaction without the special enhancement for the 10.6 MeV