Calculation of the ³He(α,γ)⁷Be astrophysical S factor using the no-core shell model with continuum including three-nucleon forces

The ³He(α,γ)⁷Be radiative-capture reaction rates between 20 and 500 keV are essential in understanding the primordial ⁷Li abundance in the universe. The Coulomb repulsion between the fusing nuclei suppresses the capture cross section at these low energies, making it difficult to measure directly. Theoretical calculations are needed to guide the extrapolation to the solar energies of interest. To this end, we present NCSMC calculations of ³He(α,γ)⁷Be reaction within the NCSMC starting from two- and three-nucleon chiral interactions.