r-Process Nuclear Physics from the Ground Up

The r-process is one of the two main nucleosynthetic processes for nature’s heaviest natural elements. Most of the nuclei involved in the r-process are too neutron-rich to have been studied experimentally, so calculations must rely on computed data from theoretical nuclear models. Differences in r-process calculations and known r-process abundances are important because they either show failings in the astrophysical or nuclear models, or both. In order to improve our understanding of how nuclear physics inputs imprint themselves on the resulting r-process abundances, we have developed simple nuclear physics models and run reaction network calculations with them. We observe how well-defined steps of increasing complexity in the nuclear physics affect reaction network dynamics and the resulting nucleosynthetic abundances. The insight provided into the role of particular nuclear physics model components on resulting abundances can help astrophysicists to understand where differences in observed and computed abundances result from nuclear physics uncertainties and not the astrophysical models, as well as guide nuclear physicists in understanding what those differences reveal about the failings of nuclear physics models.