Impact of nuclear mass models on r-process nucleosynthesis and heavy element abundances in r-process-enhanced metal-poor stars

¹ Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871, China
² Guangxi Key Laboratory for Relativistic Astrophysics, School of Physical Science and Technology, Guangxi University, Nanning 530004, China
³ Guangxi Key Laboratory of Nuclear Physics and Technology, Department of Physics, Guangxi Normal University, Guilin 541004, China

^⋆ Corresponding authors; physcmh@pku.edu.cn, lew@gxu.edu.cn

Received: 26 August 2024
Accepted: 21 November 2024

Abstract

Because we lack experimental data on extremely neutron-rich nuclei, theoretical values derived from nuclear physics models are essential for the rapid neutron-capture process (r-process). Metal-poor stars enriched by the r-process offer valuable cases for studying the impact of nuclear physics models on r-process nucleosynthesis. This study analyzes four widely used nuclear physics models in detail: the finite-range droplet model, the Hartree-Fock-Bogoliubov, the Duflo-Zuker, and the Weizsäcker-Skyrme model. Theoretical values predicted by the Weizsäcker-Skyrme model are found to agree well with experimental data, and the deviations are significantly smaller than those predicted by other models. The heavy element abundances observed in r-process-enhanced metal-poor stars can be accurately reproduced by r-process nucleosynthesis simulations using the Weizsäcker-Skyrme model, particularly for the rare-earth elements. This suggests that nuclear data provided by a nuclear physics model such as that of Weizsäcker-Skyrme are both essential and crucial for r-process nucleosynthesis studies.