Folding Model Study of the Elastic Alpha-alpha Scattering at Low Energies

The folding model analysis of the elastic \(\alpha + \alpha\) scattering at the incident energies below the reaction threshold of 34.7 MeV (in the lab system) has been done using the well-tested density dependent versions of the M3Y interaction and realistic choices for the \(^4\)He density. Because the absorption is negligible at the energies below the reaction threshold, we were able to probe the \(\alpha + \alpha\) optical potential at low energies quite unambiguously and found that the α + α overlap density used to construct the density dependence of the M3Y interaction is strongly distorted by the Pauli blocking. This result gives possible explanation of a long-standing inconsistency of the double-folding model in its study of the elastic \(\alpha + \alpha\) and \(\alpha\)-nucleus scattering at low energies using the same realistic density dependent M3Y interaction.