Nuclear masses near $N=82$ that influence $r$-process abundances

TL;DR

This paper investigates how uncertainties in nuclear masses near the neutron number N=82 affect r-process abundance predictions, identifying key nuclei influencing nucleosynthesis in astrophysical environments.

Contribution

The study conducts mass sensitivity analyses near N=82 using the FRDM model, highlighting influential nuclei and their impact on r-process abundance calculations.

Findings

Identified key nuclei near N=82 affecting r-process abundances.

Mass uncertainties propagate significantly to abundance predictions.

Results are robust across multiple astrophysical scenarios.

Abstract

Nuclear masses are one of the key ingredients of nuclear physics that go into astrophysical simulations of the $r$ process. Nuclear masses effect $r$-process abundances by entering into calculations of Q-values, neutron capture rates, photo-dissociation rates, beta-decay rates, branching ratios and the properties of fission. Most of the thousands of short-lived neutron-rich nuclei which are believed to participate in the $r$ process lack any experimental verification, thus the identification of the most influential nuclei is of paramount importance. We have conducted mass sensitivity studies near the $N=82$ closed shell in the context of a main $r$-process. Our studies take into account how an uncertainty in a single nuclear mass propagates to influence the relevant quantities of neighboring nuclei and finally to $r$-process abundances. We identify influential nuclei in various astrophysical conditions using the FRDM mass model. We show that our conclusions regarding these key nuclei are still retained when a superposition of astrophysical trajectories is considered.