A drop in the Li6(p,γ)Be7 reaction at low energies

The low-energy astrophysical S factors of the Li6(p,γ)Be7 reaction have been investigated on a 320 kV platform at the Institute of Modern Physics in Lanzhou. The experimental S factor of this reaction shows an interesting sizable drop contrary to any existing theoretical expectations at energies below 200 keV. Such drop has not been fully understood yet and may reflect a novel reaction mechanism. The appearance of an interesting new positive-parity 1/2+ or 3/2+ resonance at Ec.m.≈195keV is discussed. This study shows the danger of extrapolating experimental data over too large an energy range and demonstrates the need for careful direct experimental studies of reaction cross sections at or near stellar energies. In addition, our new results are discussed in the framework of a SUSY assisted Big-Bang Nucleosynthesis (BBN) model.