Interpretation of the anomaly in the diffuseness parameter of the Woods–Saxon potential for light fusion reactions using the effects of nuclear matter equation of state

Abstract

The present study has been aimed at understanding the role of nuclear matter (NM) incompressibility effects on the description of the problem of the abnormally large diffuseness parameter of the Woods–Saxon (WS) potential for the fusion reactions induced by the light-mass nuclei. In order to assess this aim, we simulate theoretically the saturation properties of NM within the framework of the double-folding (DF) model for a total of 26 colliding systems with condition 64 ≤ Z1Z2≤ 204 for charge product of their participant nuclei. It is shown that the DF model supplemented with the effects of nuclear matter equation of state (EOS) provides an appropriate description for measured fusion cross sections of our selected systems at around and above barrier energies. We find that the diffuseness parameters of the equivalent WS potential fitted to the DF model in the fusion barrier region are ranging from 0.62 to 0.71 fm, whereas this range is increased to aWS=0.66−0.81 fm after modeling the incompressibility effects. Our results show that the extracted values of the diffuseness parameter based on the modified form of the DF model follow an increasing trend with the charge product Z1Z2. We also present for the first time a discussion on a decreasing linear dependence of the diffuseness parameter of the nucleus–nucleus potential on the nuclear incompressibility constant K.