The γ-process nucleosynthesis in core-collapse supernovae

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 gamma-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 gamma-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 gamma-process sites and focusing on progenitors of CCSNe that experience a C-O shell merger just before the collapse of the Fe core.