Determination of S[sub 17](0) from transfer reactions

Abstract

The S-factor for the direct capture reaction 7Be(p,γ)8B can be found at astrophysical energies from the asymptotic normalization coefficients which provide the normalization of the tails of the overlap functions for 8B→7Be+p. Peripheral transfer reactions offer a technique to determine these asymptotic normalization coefficients. As a test of the technique, the 16O(3He,d)17F reaction has been used to determine asymptotic normalization coefficients for transitions to the ground and first excited states of 17F. The S-factors for 16O(p,γ)17F calculated from these 17F→16O+p asymptotic normalization coefficients are found to be in very good agreement with recent measurements. Following the same technique, the 10B(7Be,8B)9Be reaction has been used to measure the asymptotic normalization coefficient for 7Be(p,γ)8B. This result provides an indirect determination of S17(0).