Asymptotic normalization coefficients for13C+p14N

Abstract

The asymptotic normalization coefficientC for the system A + p $ B specifies the amplitude of the single-proton tail of the wave function for nucleus B when the core A and the proton are separated by a distance large compared to the strong interaction radius. In previous reports (1,2), we have shown that knowledge of asymptotic normalization coefficients (ANC's) can be used to calculate the direct capture rates for (p,) or (�,) reactions of astrophysical interest when the captured p oris relatively loosely bound in the final nucleus. The required ANC's can often be measured in peripheral transfer reactions. We are using the ANC technique to determine the astrophysical S- factor S17(0) for the proton radiative capture reaction 7 Be(p,) 8 B at solar energies, using the transfer reactions 10 B( 7 Be, 8 B) 9 Be and 14 N( 7 Be, 8 B) 13 C. In order to extract the ANC for 7 Be + p ! 8 B from these measurements, we must know the ANC's for the 9 Be + p ! 10 B and 13 C + p ! 14 N systems. We report below a study of 14 N + 13 C elastic scattering and the proton exchange reaction 13 C( 14 N, 13 C) 14 N at 162 MeV, from which we find the ANC's corresponding to 13 C +p ! 14 N. The experiment is similar to our measurement of the 9 Be+p ! 10 B ANC's reported earlier (3). Below we present details of the experiment. This is followed by a discussion of the optical model parameters extracted from the elastic scattering data and then the results for the ANC's found from the proton exchange reaction.