Excitation of three isospin modes of the giant magnetic dipole resonance in mass 24 isobars

All three isospin modes of two $T=1, 1^{+}$ states in mass 24 have been studied by (${}_{}{}^3{}_{}{}^{}\mathrm{He},t$), (${}_{}{}^3{}_{}{}^{}\mathrm{He}$, ${}_{}{}^3{}_{}{}^{}\mathrm{He}\prime$), and ($t,{}_{}{}^3{}_{}{}^{}\mathrm{He}$) reactions on ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$. The relative strengths of the two $1^{+}$ states in each reaction agree with the relative strengths of the electromagnetic transitions, but the shapes and magnitudes of the charge-exchange data are not as predicted by a one-step interaction with a central force. It is necessary to perform a two-step coupled-channel Born-approximation calculation via intermediate ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ channels using mixed wave functions to account for the results.

NUCLEAR REACTIONS ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}({}_{}{}^3{}_{}{}^{}\mathrm{He},t)$, ($t,{}_{}{}^3{}_{}{}^{}\mathrm{He}$), (${}_{}{}^3{}_{}{}^{}\mathrm{He}$, ${}_{}{}^3{}_{}{}^{}\mathrm{He}\prime$) to $1^{+}$ states. Members of isospin multiplet. Giant $M1\mathrm{}$ states. DWBA, CCBA analysis.