Abundance Uncertainties Obtained With the PizBuin Framework For Monte Carlo Reaction Rate Variations

TL;DR

This paper presents a Monte Carlo framework to quantify uncertainties in astrophysical reaction rates and their impact on nucleosynthesis models, revealing that uncertainties often stay within a factor of two despite complex reaction networks.

Contribution

The paper introduces the PizBuin Monte Carlo framework for assessing reaction rate uncertainties in nucleosynthesis, accounting for temperature-dependent errors and nuclear excitation effects.

Findings

Uncertainties can exceed experimental errors due to nuclear excitation and reaction combinations.

Total uncertainties generally stay within a factor of two across different stellar processes.

Certain nuclides with complex production pathways show larger uncertainties.

Abstract

Uncertainties in nucleosynthesis models originating from uncertainties in astrophysical reaction rates were estimated in a Monte Carlo variation procedure. Thousands of rates were simultaneously varied within individual, temperature-dependent errors to calculate their combined effect on final abundances. After a presentation of the method, results from application to three different nucleosynthesis processes are shown: the $\gamma$-process and the s-process in massive stars, and the main s-process in AGB stars (preliminary results). Thermal excitation of nuclei in the stellar plasma and the combined action of several reactions increase the final uncertainties above the level of the experimental errors. The total uncertainty, on the other hand, remains within a factor of two even in processes involving a large number of unmeasured rates, with some notable exceptions for nuclides whose production is spread over several stellar layers and for s-process branchings.