INFLUENCE OF RESONANT CHANNELS ON SUBBARRIER HEAVY-ION FUSION

The subbarrier fusion of heavy ions is discussed when one of the nuclei is excited to a resonant state. The effect of the width of the resonant state on the barrier penetration is calculated within a schematic model. It is concluded that the width could either enhance or hinder the fusion probability, depending on the relative importance of the spreading to escape parts of the width. Application of the theory to the fusion of Li11 with Pb208 at near-barrier energies is made. The resulting fusion cross section calculated with coupling to the soft giant dipole state in Li11 was found to be more than an order of magnitude smaller, in the barrier region, and larger, at subbarrier energies, than the uncoupled one. © 1995 The American Physical Society.