Direct reaction analysis ofF19(p,a)16O below the Coulomb barrier

The reaction ${}_{}{}^{19}{}_{}{}^{}\mathrm{F}$(p,α${)}^{16}$O (g.s.) is analyzed in terms of the distorted-wave Bonn approximation at energies below the Coulomb barrier. We calculate differential cross sections at 250, 350, and 450 keV as well as excitation functions between 150 and 850 keV and compare with experimental data. The astrophysical S factor is determined. We conclude that a direct reaction mechanism alone can account for the observed sub-Coulomb cross section below about 500 keV.