Asymptotic normalization coefficient for α+d →6Li from the peripheral direct capture d(α,γ)6 reaction and the astrophysical S factor at Big Bang energies

The results of the analysis of the new experimental astrophysical S factors Sexp24(E) [D. Trezzi, et al., Astropart. Phys. 89, 57 (2017)] and those measured earlier [R. G. Robertson, et al., Phys. Rev. Lett. 47, 1867 (1981)] for the nuclear-astrophysical d(α,γ)6Li reaction directly measured at extremely low energies E, are presented. New estimates and their uncertainties have been obtained for values of the asymptotic normalization coefficient for α + γ → 6Li and for the direct astrophysical S factors at Big Bang energies.

ANC experiments for nuclear astrophysics

Among the indirect methods to determine nuclear cross-section present in literature, the so-called Asymptotic Normalization Coefficient (ANC) has proven to be useful in retrieving the direct part of a radiative capture cross-section in reactions of interest for astrophysics. In this work, the method will be presented, and some results obtained in collaboration between NPI CAS and INFN-LNS will be presented.

Determination of the asymptotic normalization coefficient (nuclear vertex constant) for α + d →6Li from the new direct measured d(α,γ)6Li data and its implication for extrapolating the d(α,γ)6Li astrophysical S factor at Big Bang energies

The results of the analysis of the new experimental astrophysical S factors [Formula: see text] [D. Trezzi et al., Astropart. Phys. 89, 57 (2017)] and those measured earlier [R. G. Robertson et al., Phys. Rev. Lett. 47, 1867 (1981)] for the nuclear-astrophysical [Formula: see text] reaction directly measured at extremely low energies [Formula: see text], which is derived within the modified two-body potential method, are presented. New estimates and their uncertainties have been obtained for values of the asymptotic normalization coefficient for [Formula: see text] and for the direct astrophysical [Formula: see text] factors at Big Bang energies.