The comparison between observational abundance features and those obtained from nucleosynthesis predictions of stellar evolution and/or explosion simulations can scrutinize two aspects: (a) the conditions in the astrophysical production site and (b) the quality of the nuclear physics input utilized. Here we test the abundance features of r-process nucleosynthesis calculations using four different fission fragment distribution models. Furthermore, we explore the origin of a shift in the third r-process peak position in comparison with the solar r-process abundances which has been noticed in a number of merger nucleosynthesis predictions. We show that this shift occurs during the r-process freeze-out when neutron captures and β-decays compete and an (n,γ)-(γ,n) equilibrium is not maintained anymore. During this phase neutrons originate mainly from fission of material above A = 240. We also demonstrate that a faster (and thus earlier) release of these neutrons, e.g., by shorter β-decay half-lives of nuclei with Z > 80, as suggested by recent theoretical advances, can partially prevent this shift.
|Title of host publication||Proceedings of Science|
|Publisher||Proceedings of Science (PoS)|
|Publication status||Published - 31 Dec 2014|
|Event||13th Nuclei in the Cosmos, NIC 2014 - Debrecen, Hungary|
Duration: 7 Jul 2014 → 11 Jul 2014
|Conference||13th Nuclei in the Cosmos, NIC 2014|
|Period||7/07/14 → 11/07/14|