Speaker
Description
The nuclear symmetry energy and its density dependence play a crucial role in defining the properties of a wide range of systems, spanning from asymmetric nuclei to neutron stars and various other astrophysical phenomena. Motivated by recent advancements, particularly the precise determination of neutron skin thickness for ${}^{208}\mathrm{Pb}$ and ${}^{48}\mathrm{Ca}$ nuclei through PREX-II and CREX, this study addresses the unresolved density dependence issue of symmetry energy, specifically focusing on the recent estimate of the slope (L0) at saturation density. We explore the density dependence of symmetry energy in sub-barrier fusion cross-sections and astrophysical $S$-factors for asymmetric nuclei. Utilizing non-relativistic and relativistic mean-field models, we generate nucleon densities across a spectrum of neutron skin thickness or L0 values. Results for O, Ca, Ni, and Sn isotopes reveal the impact of symmetry energy behaviour and neutron skin thickness on barrier parameters, cross-sections, and astrophysical $S$-factors. Particularly, cross-sections for neutron-rich nuclei exhibit pronounced dependence on symmetry energy and neutron skin thickness. Increased skin thickness lowers barrier height and width, significantly enhancing $S$-factor values. This investigation offers insights into the complex interplay of density dependence in symmetry energy and reaction parameters, contributing to our understanding of asymmetric nuclei in sub-barrier fusion reactions.
