Neutron-capture measurement candidates for the r-process in neutron star mergers

Abstract

Neutron star mergers (NSMs) are one of the astrophysical sites for the occurrence of the rapid neutron capture process (r-process). After a merger, the ejected neutron-rich matter hosts the production of radioactive heavy nuclei located far from the stability valley. Their nuclear physics properties are key inputs for r-process nucleosynthesis calculations. Here, we focus on the importance of neutron-capture rates and perform a sensitivity study for typical outflows from NSMs. We identify the rates with the highest impact on the final r-process abundance pattern and the nuclear energy release, therefore determining the nucleosynthesis in NSMs. A list of major n-capture rates affecting individual isotopes and elements production is also provided.

Nuclear Uncertainties Associated with the Nucleosynthesis in Ejecta of a Black Hole Accretion Disk

“…Such nuclei reside much closer to stability than the maximal rprocess path, which typically hits the neutron drip line (Mumpower et al 2012). Indeed, sensitivities to capture rates found in the intermediate i-process nucleosynthesis often overlap with sensitivities in the r-process (Surman et al 2014;Denissenkov et al 2018;Vescovi et al 2022).…”

Neutron captures in stellar nucleosynthesis

“…To that purpose, sensitivity studies aiming at identifying the most important nuclear properties to be measured in order to reduce the uncertainty related to the r-process are particularly helpful (see e.g. [19]). Sensitivity studies play a key role in facilitating state-of-the-art measurements as they provide crucial astrophysical motivation to focus experimental campaigns on the most impactful nuclei.…”