Heavy-ion charge exchange reactionSi28(O18,F18)Al28

The angular distribution has been measured for the $3^{+}$ and $2^{+}$ ground state doublet in ${}_{}{}^{28}{}_{}{}^{}\mathrm{Al}$ with the heavy-ion charge exchange reaction ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$(${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{18}{}_{}{}^{}\mathrm{F}$)${}_{}{}^{28}{}_{}{}^{}\mathrm{Al}$ at the incident beam energy of 56 MeV. It has been analyzed in terms of the microscopic one-step direct charge exchange model and the second-order DWBA approach with recoil effect taking into account the two-successive transfer: one nucleon stripping and pickup, and pickup and stripping process. The general shape of angular distribution has been reproduced by both approaches. The strength of the spin-isospin dependent two-body interaction potential extracted from one-step calculations is close to the upper limit of uncertainties reported in the light-ion charge exchange experiment. The two-step mechanism turns out to be also important and could be a competing process.