An explanation for the anomaly problem of diffuseness parameter of the nucleus-nucleus potential in heavy-ion fusion reactions: A possible thermal solution

Abstract

We present an explanation for the abnormally large diffuseness parameter of the Woods-Saxon (WS) potential in heavy-ion fusion reactions based on the thermal considerations of the ion-ion potential. Within the framework of the temperature-dependent (TD) form of the proximity potential 2010, we systematically explored the role of the thermal effects in the fusion excitation functions of a significant number of the heavy-ion fusion reactions. The obtained results reveal that the proximity potential supplemented with temperature effects has been successful in reproducing the fusion excitation data for various considered systems. Based on the TD nucleus-nucleus potentials, we extract the equivalent diffuseness parameter of the WS potential. The extracted values are ranging between 0.63 fm and 1.09 fm. We also show the diffuseness parameter follows a regular decreasing trend with increase of the temperature T.