Extrapolation of the astrophysical S factor for 7Be(p,γ)8B to solar energies

We investigate the energy dependence of the astrophysical S factor for the reaction 7Be(p,γ)8B, the primary source of high-energy solar neutrinos in the solar pp chain. Below 400 keV the energy dependence is well understood in terms of a subthreshold pole arising from the binding of the valence proton to the 8B ground state.