Radiative capture of nucleons at astrophysical energies with single-particle states

TL;DR

This paper calculates radiative nucleon capture cross sections and astrophysical S-factors for light nuclei (A<20) using a single-particle model, providing insights into reaction mechanisms relevant for nucleosynthesis.

Contribution

It introduces a simplified two-body model for direct radiative capture, fitting parameters and validating results against experimental data for light nuclei.

Findings

Model successfully reproduces experimental cross sections for several nuclei.

Spectroscopic factors and asymptotic normalization coefficients are extracted and compared.

The approach identifies cases where the single-particle model is most effective.

Abstract

Radiative capture of nucleons at energies of astrophysical interest is one of the most important processes for nucleosynthesis. The nucleon capture can occur either by a compound nucleus reaction or by a direct process. The compound reaction cross sections are usually very small, specially for light nuclei. The direct capture proceeds either via the formation of a single-particle resonance, or a non-resonant capture process. In this work we calculate radiative capture cross sections and astrophysical S-factors for nuclei in the mass region A<20 using single-particle states. We carefully discuss the parameter fitting procedure adopted in the simplified two-body treatment of the capture process. Then we produce a detailed list of cases for which the model works well. Useful quantities, such as spectroscopic factors and asymptotic normalization coefficients, are obtained and compared to published data.