Astrophysical S17(0) factor extraction from breakup of 8B on 58Ni at energies near the Coulomb barrier

Abstract

We have performed continuum-discretized coupled channels (CDCC) calculations of the breakup of 8B on 58Ni and direct proton transfer for the 8B+58Ni system at laboratory energies of 20-28.4 MeV. The influence of the 7Be core-target optical potential (OP) on the breakup cross section was investigated. Elastic scattering angular distributions for the 7Be+58Ni and 8B+58Ni systems at five different energies around the Coulomb barrier were studied, and a reasonable energy-independent OP for each system was obtained. Using these OPs and two different 7Be-p relative motion wave functions, and summing breakup and direct proton transfer contributions, we were able to fit the experimental cross section at a 8B laboratory energy of 25.75 MeV. We calculated the excitation function for the 7Be emission in the 8B+58Ni reaction, where 7Be products were measured at the forward angle θlab=45° in the energy interval Elab=20-28.4 MeV. In view of the peripheral character of the B8 breakup reaction at near-barrier energies, we could extract the asymptotic normalization coefficient for the 7Be-p system, which was found to be CBe-p,p3/22=0.543±0.027 fm-1. Finally, the astrophysical S17(0) factor was found to be S17(0)=20.8±1.1 eV b.