Sensitivity of the r-process rare-earth peak abundances to nuclear masses

Abstract

The sensitivity of the r-process rare-earth peak abundances to nuclear masses has been studied in different astrophysical scenarios. The most impactful nuclei lie along the r-process paths at r-process freeze-out and at the time when the neutron-capture timescale is approximately 3 times of the β-decay timescale (τnγ≈3τβ), corresponding to the onset and completion of rare-earth peak formation, respectively. In astrophysical scenario with fission involved, the sensitivities for nuclei lying along the r-process path at freeze-out are masked by the large contribution of fission products to the rare-earth peak abundances. This work provides recommended targets for future researches and thus helps to increase the understanding of rare-earth peak formation mechanism and the efficacy of the rare-earth peak as an r-process site diagnostic.