Nuclear Weak Rates and Detailed Balance in Stellar Conditions

TL;DR

This paper investigates the validity of detailed balance in nuclear weak transitions under astrophysical conditions, showing that violations do not significantly affect reaction rate calculations at high temperatures.

Contribution

It demonstrates that nuclear weak rate calculations can remain robust despite violations of detailed balance in non-equilibrium astrophysical environments.

Findings

Shell model calculations of weak strengths at high temperatures

Reaction rates remain accurate despite detailed balance violations

Discussion on weak equilibrium relevance in stellar conditions

Abstract

Detailed balance is often invoked in discussions of nuclear weak transitions in astrophysical environments. Satisfaction of detailed balance is rightly touted as a virtue of some methods of computing nuclear transition strengths, but we argue that it need not necessarily be strictly obeyed, especially when the system is far from weak equilibrium. We present the results of shell model calculations of nuclear weak strengths in both charged current and neutral current channels at astrophysical temperatures. Using these strengths to compute some reaction rates, we find that, despite some violation of detailed balance, our method is robust up to high temperature, and we comment on the relationship between detailed balance and weak equilibrium in astrophysical conditions.