%0 Journal Article
%A Fraile Prieto, Luis Mario
%A Gallardo, M. C.
%A Vedia Fernández, María Victoria
%A otros, ...
%T First Accurate Normalization of the β-delayed α Decay of N-16 and Implications for the C-12(α,γ)O-16 Astrophysical Reaction Rate
%D 2018
%@ 0031-9007
%U https://hdl.handle.net/20.500.14352/13134
%X The C-12(alpha,gamma)O-16 reaction plays a central role in astrophysics, but its cross section at energies relevant for astrophysical applications is only poorly constrained by laboratory data. The reduced a width, gamma(11), of the bound 1(-) level in O-16 is particularly important to determine the cross section. The magnitude of gamma(11) is determined via sub-Coulomb a-transfer reactions or the beta-delayed a decay of N-16, but the latter approach is presently hampered by the lack of sufficiently precise data on the beta-decay branching ratios. Here we report improved branching ratios for the bound 1(-) level [b(beta,11) = (5.02 +/- 0.10) x 10(-2)] and for beta-delayed alpha emission [b(beta alpha) = (1.59 +/- 0.06) x 10(-5)]. Our value for b(beta alpha) is 33% larger than previously held, leading to a substantial increase in gamma(11). Our revised value for gamma(11) is in good agreement with the value obtained in a-transfer studies and the weighted average of the two gives a robust and precise determination of gamma(11), which provides significantly improved constraints on the C-12(alpha,gamma) cross section in the energy range relevant to hydrostatic He burning.
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