Density-dependence of effective n-n forces and the hindrance in extreme sub-barrier fusion

Abstract

We present our investigations of double‐folding, heavy‐ion potentials and of the role played by nucleon‐nucleon interactions that incorporate medium effects in accordance with the saturation properties of nuclear matter. The dependence on the medium is included directly via a repulsive term in the heavy‐ion potential, and/or via a density dependent term as in the case of zero‐or finite‐range forces in mean‐field nuclear structure calculations. We illustrate this point with the coupled‐channels calculations we performed for systems that display a hindrance in fusion at deep sub‐barrier energies.