Impact of few-body reactions on explosive nucleosynthesis: the big-bang and supernovae

We study the few body reactions in explosive nucleosynthesis of light-to-heavy mass elements in various astrophysical conditions. In neutrino-driven winds of gravitational core collapse of SNeII, several light nuclei as well as heavy unstable nuclei play significant roles in producing r-process elements. We discuss how the three-body reaction 4He(αn, γ)9Be, whose cross section is poorly known, plays very critical role. We make note that several other reactions in the r-process are relevant to a big-bang nucleosynthesis. We discuss briefly a galactic chemical evolution. (author)