The lightest chemical elements –Hydrogen and Helium– were created about a minute after the Big Bang. Elements up to Iron are forged by fusion reactions in stars. Heavy elements between Iron and Uranium are produced by a sequence of neutron captures and beta-decays known as rapid neutron capture or r process. The freshly synthesized r-process elements undergo radioactive decay through various channels depositing energy in the ejecta that powers an optical/infrared transient called “kilonova” whose basic properties like luminosity and its dependence on ejecta mass, velocity, radioactive energy input, and atomic opacities have been dramatically confirmed by the observation of a kilonova electromagnetic transient associated with the gravitational wave signal GW170817. It provided the first direct indication that r-process elements are produced in neutron-star mergers. Additional events are expected to be detected in the following years, representing a complete change of paradigm in r-process research as for the first time we will be confronted with direct observational data. To fully exploit such opportunity, it is fundamental to combine an improved description of exotic neutron-rich nuclei involved in the r-process with sophisticated astrophysical simulations to provide accurate prediction of r-process nucleosynthesis yields and their electromagnetic signals to be confronted with observational data. We will further exploit the unique experimental capabilities of the GSI/FAIR facility, to advance our understanding of r-process nucleosynthesis and determine the contribution of mergers to the chemical enrichment of the galaxy in heavy elements.
