Fission and the r-process nucleosynthesis in neutron star mergers

The rapid neutron capture process (r process) is responsible for the production of half of the elements heavier than iron that we observe in the Universe. The quest to identify its actual astrophysical site is still ongoing, but there are strong indications including the recent observation of the GW170817 electromagnetic counterpart that make neutron star mergers (NSM) a likely candidate. Reliable estimates of nucleosynthesis yields on NSM require an accurate description of the relevant nuclear physics inputs, including fission properties of heavy and superheavy nuclei. In this talk I will present a recent calculation of the fission properties of nuclei in the range 84 ≤ Z ≤ 120 and 120 ≤ N ≤ 250 calculated using the nuclear energy density functional theory (EDF). A new set of spontaneous, neutron-induced and beta-delayed fission rates are obtained from a microscopic calculation of the fission barriers and collective inertias. These fission rates are used as a nuclear input in r-process calculations in NSM. This constitutes a first step in a systematic exploration of different sets of fission rates on r-process abundance predictions.