The γ-process nucleosynthesis in core-collapse super-novae

Abstract

Neutron-capture processes made most of the abundances of heavy elements in the Solar System, however they cannot produce a number of rare proton-rich stable isotopes (p–nuclei) lying on the left side of the valley of stability. The γ–process, i.e., a chain of photodisintegrations starting on heavy nuclei, is recognized and generally accepted as a feasible process for the synthesis of p–nuclei in core collapse supernovae (CCSNe). However this scenario still leaves some puzzling discrepancies between theory and observations. We aim to explore in more detail the γ–process production from massive stars, using different sets of CCSNe models and the latest nuclear reaction rates. Here we show our preliminary analysis, by identifying the γ–process sites and focusing on progenitors of CCSNe that experience a C–O shell merger just before the collapse of the Fe core.