The s-process nucleosynthesis in low mass stars: impact of the uncertainties in the nuclear physics determined by Monte Carlo variations

TL;DR

This study assesses how uncertainties in nuclear reaction rates influence s-process nucleosynthesis in low-mass stars, highlighting neutron capture rates as the dominant source of abundance variability.

Contribution

It introduces a Monte Carlo-based method to quantify the impact of nuclear physics uncertainties on stellar nucleosynthesis predictions.

Findings

Neutron capture rate uncertainties cause about 50% variation in final abundances.

Beta-decay rate uncertainties mainly affect nuclides near s-process branchings.

Reactions on heavy elements significantly influence nucleosynthesis outcomes.

Abstract

We investigated the impact of uncertainties in neutron-capture and weak reactions (on heavy elements) on the s-process nucleosynthesis in low-mass stars using a Monte-Carlo based approach. We performed extensive nuclear reaction network calculations that include newly evaluated temperature-dependent upper and lower limits for the individual reaction rates. Our sophisticated approach is able to evaluate the reactions that impact more significantly the final abundances. We found that beta-decay rate uncertainties affect typically nuclides near s-process branchings, whereas most of the uncertainty in the final abundances is caused by uncertainties in neutron capture rates, either directly producing or destroying the nuclide of interest. Combined total nuclear uncertainties due to reactions on heavy elements are approximately 50%.