Speaker
Description
The astrophysical rapid neutron capture process, the r process, has produced around half of the elements heavier than iron but yet its astrophysical sites are not well known. Neutron star (NS) mergers (either NS-NS or NS-black hole), which can eject synthesized material either dynamically during the merger or from the accretion disks around the central remnant, are currently considered as the most promising r-process sites. In addition to mergers, neutrino-driven winds from proton-neutron stars resulting from core-collapse supernovae may contribute via the weak r-process. Alternative scenarios, such as magnetorotational supernovae, have also been suggested to explain the observed r-process pattern in very old (low metallicity) stars for which the binary mergers evolve too slowly.
The formation of the r-process nuclei and the calculated r-process abundances depend strongly on the properties of neutron-rich nuclei, such as their binding energies (masses), beta-decay half-lives and neutron-capture rates. Recently, several r-process sensitivity studies on these properties have indicated that the nuclei near the closed neutron shells at N=82 and N=126 corresponding the second and third r-process peaks have the highest impact. In addition, the formation of the rare-earth peak is very sensitive both to nuclear structure effects in the mid-shell region around N=104 and to the astrophysical environment. In summary, increasing our knowledge of neutron-rich nuclei provides essential data both for understanding the evolution of nuclear structure as well as for constraining the r-process calculations and ultimately the r-process site(s).
In this talk, I will review the formation and structure of the r-process nuclei, and discuss possibilities within the EURISOL-DF and its partner facilities to further our knowledge on this topic.
