Heavy-ion charge exchange reaction /sup 28/Si(/sup 18/O,/sup 18/F)/sup 28/Al

The angular distribution has been measured for the 3/sup +/ and 2/sup +/ ground state doublet in /sup 28/Al with the heavy-ion charge exchange reaction /sup 28/Si(/sup 18/O,/sup 18/F)/sup 28/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-step 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.