Constraining the 6.05 MeV 0${}^{+}$ and 6.13 MeV 3${}^{-}$ cascade transitions in the ${}^{12}$C($\alpha$,$\gamma$)${}^{16}$O reaction using the Asymptotic Normalization Coefficients

Abstract

Background. The ${}^{12}$C$(\alpha ,\gamma {)}^{16}$O reaction plays a fundamental role in astrophysics and needs to be known with accuracy better than 10%. Cascade $\gamma$ transitions through the excited states of ${}^{16}$O are contributing to the uncertainty. Purpose. To constrain the contribution of the 0${}^{+}$ (6.05 MeV) and 3${}^{-}$ (6.13 MeV) cascade transitions. Method. The $\alpha$ Asymptotic Normalization Coefficient for these states were measured using the $\alpha$-transfer reaction ${}^{12}$C${(}^6$Li,$d{)}^{16}$O at sub-Coulomb energies. Results. The 0${}^{+}$ and 3${}^{-}$ cascade transitions contribution was found to be 1.96$\pm$0.3 keV b and 0.12$\pm$0.04 keV b for destructive interference of the direct and resonance capture and 4.36$\pm$0.45 keV b and 1.44$\pm$0.12 keV b for constructive interference respectively. Conclusions. The combined contribution of the 0${}^{+}$ and 3${}^{-}$ cascade transitions to the reaction at 300 keV does not exceed 4%. Significant uncertainties have been dramatically reduced.

References in corpus (2)

• On the 14C(alpha,gamma) reaction rate
• $\alpha$-cluster ANCs for nuclear astrophysics

Cited by in corpus (1)

• New $\alpha$ ANC measurement of the 1/2${}^{+}$ state in ${}^{17}$O at 6.356 MeV, that dominates the ${}^{13}$C($\alpha$,n)${}^{16}$O reaction rate at temperatures relevant for the s-process