Extended quantum diffusion approach to reactions of astrophysical interests

TL;DR

This paper extends the quantum diffusion model to low-energy nuclear fusion reactions relevant in astrophysics, providing analytic expressions and improved agreement with experimental data for sub-barrier capture cross-sections.

Contribution

It introduces an energy-dependent friction parameter into the quantum diffusion approach and compares its predictions with WKB calculations in the astrophysical S-factor.

Findings

Good agreement with experimental fusion cross-sections

Analytic expression for sub-barrier capture probability

Comparison of quantum diffusion and WKB approaches

Abstract

The quantum diffusion approach is extended to low energy fusion (capture) reactions of light- and medium-mass nuclei. The dependence of the friction parameter on bombarding energy is taken into account. A simple analytic expression is obtained for the capture probability at extreme sub-barrier energies. The calculated cross-sections are in a good agreement with the experimental data. The fusion excitation functions calculated within the quantum diffusion and WKB approaches are compared and presented in the astrophysical $S$-factor representation.