Coupled-channel effects in 12C + 12C scattering

The scattering of 12C + 12C is studied within the coupled-channels framework. Different models are discussed for the transition density of the 2+ state in 12C at 4.44 MeV. These densities are used to calculate the transition potentials needed within the double folding model framework, using the M3Y-effective interaction. This method gives a good description of the elastic and inelastic scattering at Esub(cm) = 51 MeV if the transition potentials are renormalized slightly. The structure seen in the fusion and inelastic excitation functions from Esub(cm) = 6 MeV to 40 MeV is considered. This potential shape is shown to give structure in the fusion and inelastic excitation functions due to the rapid increase in penetrability at the incident energies which correspond to the barrier heights. The effects of strong coupling on the structure seen are studied in detail. The coupling increases the fusion cross-section compared to the reaction cross-section found in an optical model calculation and can change the structure substantially. (author)