Variances in r-process predictions from uncertain nuclear rates

Abstract

Rapid neutron capture or ‘r-process’ nucleosynthesisis a critical process for creating approximately half of heavy elements above iron in the Universe. Simulations of the r- process require theoretical calculations of neutron capture and, β-decay rates for thousands of short-lived nuclei for which no experimental data exists. We explore the impact of uncertainties in theoretical nuclear rates by performing global monte carlo simulations. We show that randomly varying neutron capture and β-decay rates within current theoretical model uncertainties results in large error bars for r-process predictions. We conclude that the reduction of rate uncertainties either by new measurements or by improved nuclear models will allow for more robust r-process predictions.