Asymptotic normalization coefficients for B-8 ---> Be-7 + p from a study of Li-8 ---> Li-7 + n

Asymptotic normalization coefficients (ANCs) for Li-8-->Li-7+n have been extracted from the neutron transfer reaction C-13(Li-7,Li-8)C-12 at 63 MeV. These are related to the ANCs in B-8-->Be-7 + p using charge symmetry. We extract ANCs for B-8 which are in very good agreement with those inferred from proton transfer and breakup experiments. We have also separated the contributions from the p(1/2) and p(3/2) components in the transfer. We find the astrophysical factor for the Be-7(p, gamma)B-8 reaction to be S-17( 0) = 17.6+/-1.7 eV b. This is the first time that the rate of a direct capture reaction of astrophysical interest has been determined through a measurement of the ANCs in the mirror system.