Weak Interaction Rates

This manuscript reviews recent progress in our understanding of the nucleosynthesis of medium and heavy elements in supernovae.Recent hydrodynamical models of core-collapse supernovae show that a large amount of proton rich matter is ejected under strong neutrino fluxes.This matter constitutes the site of the ν p-process where antineutrino absorption reactions catalyze the nucleosynthesis of nuclei with A > 64.Supernovae are also associated with the r-process responsible for the synthesis of the heaviest elements in nature.Fission during the r-process can play a major role in determining the final abundance patter and in explaining the almost universal features seen in metal-poor r-process-rich stars.