Alpha scattering and capture reactions in theA=7 system at low energies

Differential cross sections for ³α scattering were measured in the energy range up to 3 MeV. These data together with other available experimental results for ³He+{α} and ³H+{α} scattering were analyzed in the framework of the optical model using double-folded potentials. The optical potentials obtained were used to calculate the astrophysical S factors of the capture reactions ³He({α},{γ})⁷Be and ³H({α},{γ})⁷Li, and the branching ratios for the transitions into the two final ⁷Be and ⁷Li bound states, respectively. For ³He({α},{γ})⁷Be excellent agreement between calculated and experimental data is obtained. For ³H({α},{γ})⁷Li an S(0) value has been found which is a factor of about 1.5 larger than the adopted value. For both capture reactions a similar branching ratio of R={σ}(γ₁)/{σ}(γ₀){}0.43 has been obtained.