Finite-range DWBA analysis of 7Li(p, α) 4He reaction at astrophysically relevant energies

Abstract

The experimental angular distributions for the reaction 7Li(p, α) 4He at incident energies of 271, 416 and 561 keV below the Coulomb barrier are analyzed with the finite-range distorted-wave-Born-approximation formalism including both the direct and the exchange processes. The spectroscopic amplitudes used in the present analysis are obtained so as to fit the experimental angular distributions for the same reaction at the proton bombarding energy of 45.2 MeV. Good agreements between theoretical calculations and experiments are obtained in regard to both the shape and the absolute magnitude of the differential cross section. Numerical calculations show that the direct-reaction mechanism is dominant for the reaction 7Li(p, α) 4He; in particular, the exchange process plays an important role for reproducing the experimental angular distributions in keV energy ranges.