Polarisation potential and sub-barrier fusion in a multiphonon excitation model

Abstract
The authors define an adiabatic polarisation potential describing the coupling to the collective vibrational states. The corrections on the folding potential are found to be very large. Correspondingly the sub-barrier fusion cross section is strongly enhanced and, for the 40Ca+40Ca system, the agreement with the experimental data is good in view of the fact that they do not have any adjustable parameters. For the asymmetric 40Ca+48Ca case, the introduction of some other degrees of freedom, like the nucleon transfer is required.