Ab initio prediction of ⁴He(d,γ)⁶Li at big-bang nucleosynthesis energies

The radiative capture ⁴He(d,γ)⁶Li is the dominant process in the Big Bang Nucleosynthesis (BBN) of ⁶Li. It therefore strongly influences the abundance ratio of ⁶Li/⁷Li., for which observational data are three orders of magnitude higher than BBN predictions. Because of the low cross section and the large experimental uncertainties, it is crucial to have accurate predictions. In this talk, I will present an ab initio calculation of ⁴He(d,γ)⁶Li [1], where all nucleons are active and interacting through chiral-EFT nucleon- and three-nucleon forces. After reviewing the ab initio no-core shell model with continuum method, I will show our results which are in excellent agreement with the recent LUNA data [2]. I will also discuss the importance of each electromagnetic transitions on ⁴He(d,γ)⁶Li at BBN energies.

[1] Hebborn et al. arXiv:2203.15914

[2] Anders et al. Phys. Rev. Lett. 113, 042501 (2014).