The Astrophysical S Factor of the p + ⁷Be Radiative Capture Reaction

One of the key nuclear processes for heavy element creation in stellar and primordial nucleosyntheses is the ⁷Be (p, \(\gamma )\) $\gamma )$ 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 \({1}^{+}\) $1^{+}$ 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.