Isovector and nonlinear term contributions of relativistic mean field models in fusion reactions

This paper focuses on constructing and analyzing the effective potential [Formula: see text] derived from the relativistic mean field (RMF) model. Our findings are compared with those from other existing models and relevant experimental data. We particularly emphasize the [Formula: see text] component of [Formula: see text] in our calculations of fusion cross-sections. To obtain quantitative results, we utilized three standard RMF parameter sets, along with recent parameter sets based on chiral effective field theory. These were applied to examine the fusion cross-sections for the reactions [Formula: see text] and [Formula: see text]. For the calculation of the double-folding potential [Formula: see text], we employed the Monte Carlo sixfold integral approach. The transfer matrix method was used to derive the cross-sections. The results for the [Formula: see text] reaction show strong agreement with the fusion cross-section obtained from experimental data and predictions made by other models. However, for the [Formula: see text] reaction, there could be better alignment with experimental data if we account for contributions beyond the mean-field approximation. This is mainly because the isovector contribution plays a minimal role in this particular reaction. Furthermore, the [Formula: see text] component of [Formula: see text] has a limited impact on the fusion cross-section, as its contribution is suppressed by the factor [Formula: see text]. In conclusion, the proposed [Formula: see text] inspired by the RMF model offers a satisfactory description of fusion reactions.