R-process nucleosynthesis calculations with complete nuclear physics input

TL;DR

This paper presents a comprehensive nuclear physics database and reaction network for r-process nucleosynthesis, aiming to understand the role of fission in producing consistent heavy element abundance patterns in astrophysical scenarios.

Contribution

It introduces the first complete database of reaction rates including fission processes and implements them in a reaction network for r-process calculations.

Findings

Fission processes can influence the robustness of the r-process pattern.

The complete database enables more accurate modeling of exotic nuclei reactions.

Implications for the astrophysical sites of heavy element synthesis.

Abstract

The r-process constitutes one of the major challenges in nuclear astrophysics. Its astrophysical site has not yet been identified but there is observational evidence suggesting that at least two possible sites should contribute to the solar system abundance of r-process elements and that the r-process responsible for the production of elements heavier than Z=56 operates quite robustly producing always the same relative abundances. From the nuclear-physics point of view the r-process requires the knowledge of a large number of reaction rates involving exotic nuclei. These include neutron capture rates, beta-decays and fission rates, the latter for the heavier nuclei produced in the r-process. We have developed for the first time a complete database of reaction rates that in addition to neutron-capture rates and beta-decay half-lives includes all possible reactions that can induce fission (neutron-capture, beta-decay and spontaneous fission) and the corresponding fission yields. In addition, we have implemented these reaction rates in a fully implicit reaction network. We have performed r-process calculations for the neutrino-driven wind scenario to explore whether or not fission can contribute to provide a robust r-process pattern.