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Vol. 53, No. 3 Astrophysical S -factors from asymptotic normalization coefficientsR E TRIBBLE, A AZHARI, H L CLARK, C A GAGLIARDI, Y-W LUI, A M MUKHAMEDZHANOV, A SATTAROY, X TANG, L TRACHE, V BURJAN, J CEJPEK * , V KROHA* ,Š PISKOR* , J VINCOUR* and F C ÂRSTOIU¨Cyclotron Institute, Texas A&M University, College Station, Texas 77843, USA ¨ Institute for Atomic Physics, Bucharest, Romania Abstract. S-factors for direct capture reactions can be found at astrophysical energies from asymptotic normalization coefficients which provide the normalization of the tail of the overlap function. For example the overlap for 8B ® 7 Be + p defines the S-factor for 7 Be (p; g ) 8B. Peripheral transfer reactions offer a technique to determine these asymptotic normalization coefficients. As a test of the technique, the 16O(3He, d)17 F 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,g)17F calculated from these 17F®16 O + p asymptotic normalization coefficients are found to be in very good agreement with recent measurements. Following the same technique, the 10 B(7Be,8B)9Be and14N(7Be,8B)13 C reactions have been used to measure the asymptotic normalization coefficient for 7 Be(p; g )8B. This result provides an indirect determination of S17 (0). Keywords. Nuclear astrophysics; S-factors. PACS Nos 25.40.Lw; 21.10.Pc; 27.20.+n; 26.65.+t; 25.55.Hp; 26.20.+f |