Stellar neutron capture reactions at low and high temperature

TL;DR

This paper reviews neutron capture reaction rates in astrophysics, focusing on differences between low and high temperature conditions, and discusses theoretical and experimental challenges in predicting these rates for various nucleosynthesis processes.

Contribution

It provides a comparative analysis of neutron capture reactions at different temperatures and discusses the nuclear physics complexities affecting reaction rate predictions.

Findings

Reaction mechanisms differ significantly between low and high temperatures.

Nuclear level densities influence reaction rate calculations.

Experimental and theoretical challenges are highlighted for accurate rate determination.

Abstract

The determination of astrophysical reaction rates requires different approaches depending on the conditions in hydrostatic and explosive burning. The focus here is on astrophysical reaction rates for radiative neutron capture reactions. Relevant nucleosynthesis processes not only involve the s-process but also the i-, r- and $\gamma$-processes, which from the nuclear perspective mainly differ in the relative interaction energies of neutrons and nuclei, and in the nuclear level densities of the involved nuclei. Emphasis is put on the difference between reactions at low and high temperature. Possible complications in the prediction and measurement of these reaction rates are illustrated and the connection between theory and experiment is addressed.