One of the key nuclear processes for heavy element creation in stellar and primordial nucleosyntheses is the 7Be (p, 8B radiative capture reaction. At very low energies, Effective Field Theory (EFT) provides a model-independent framework for describing physical observables. At the energy range studied, we calculated the S-factor for the E1 transition of the p + 7Be Radiative Capture Reaction (0–0.5 MeV). The leading M1 contribution is relevant at energies 600 keV around the resonance, although it is negligible. In comparison to other experimental and theoretical investigations, the astrophysical S factor values extrapolated to zero energy are determined to be S17 (0) = 20.90 eV.b and S17*(0) = 21.13 eV.b for EFT and EFT*, respectively.
