Astrophysical S factor for the radiative capture 12N(p,gamma)13O determined from the 14N(12N,13O)13C proton transfer reaction

摘要

The cross section of the radiative proton capture reaction on the drip linenucleus 12N was investigated using the Asymptotic Normalization Coefficient(ANC) method. We have used the 14N(12N,13O)13C proton transfer reaction at 12MeV/nucleon to extract the ANC for 13O -> 12N + p and calculate from it thedirect component of the astrophysical S factor of the 12N(p,gamma)13O reaction.The optical potentials used and the DWBA analysis of the proton transferreaction are discussed. For the entrance channel, the optical potential wasinferred from an elastic scattering measurement carried out at the same timewith the transfer measurement. From the transfer, we determined the square ofthe ANC, C^2(13Og.s.) = 2.53 +/- 0.30 fm-1, and hence a value of 0.33(4) keVbwas obtained for the direct astrophysical S factor at zero energy. Constructiveinterference at low energies between the direct and resonant captures leads toan enhancement of Stotal(0) = 0.42(5) keVb. The 12N(p,gamma)13O reaction wasinvestigated in relation to the evolution of hydrogen-rich massive PopulationIII stars, for the role that it may play in the hot pp-chain nuclear burningprocesses, possibly occurring in such objects.