The impact of individual nuclear masses on $r$-process abundances

TL;DR

This study systematically examines how variations in individual nuclear masses influence r-process nucleosynthesis outcomes, highlighting key nuclei that significantly affect abundance predictions across different astrophysical scenarios.

Contribution

It is the first comprehensive analysis linking nuclear mass uncertainties to r-process abundance variations, using the 2012 Finite-Range Droplet Model.

Findings

Mass variations can cause up to tenfold changes in abundance patterns.

Identified key nuclei with significant impact on r-process predictions.

Results applicable to hot, cold, and neutron star merger scenarios.

Abstract

We have performed for the first time a comprehensive study of the sensitivity of $r$-process nucleosynthesis to individual nuclear masses across the chart of nuclides. Using the latest version (2012) of the Finite-Range Droplet Model, we consider mass variations of $\pm0.5$ MeV and propagate each mass change to all affected quantities, including $Q$-values, reaction rates, and branching ratios. We find such mass variations can result in up to an order of magnitude local change in the final abundance pattern produced in an $r$-process simulation. We identify key nuclei whose masses have a substantial impact on abundance predictions for hot, cold, and neutron star merger $r$-process scenarios and could be measured at future radioactive beam facilities.