Collective neutrino flavor oscillations and supernova nucleosynthesis in proton-rich gas flows

In core-collapse supernovae, non-linear effects are caused by self-interacting neutrinos emitted from the proto-neutron star. These many-body effects induce collective neutrino oscillations and dramatic flavor changes in neutrino fluxes which will have crucial effects on ν-process in outer layers or explosive nucleosynthesis such as r-process and νp-process in neutrino-driven winds. We have studied collective neutrino oscillations in the realistic 3 flavor multi-angle calculation using the simulation data of 1D explosion model. We have also applied these oscillation results to the nucleosynthesis in a proton-rich gas trajectory consistently. Especially, in normal neutrino mass hierarchy, we find the enhancement of the ν_e flux caused by collective neutrino oscillations before νp-process proceeds actively. Therefore, νp-process is triggered by more free neutrons produced by the ν_e absorption on protons and this nucleosynthesis is successful to raise up the abundances of lighter p-nucleus such as Se, Kr, and Sr greatly. Heavier p-nucleus like ⁹²Mo and ⁹⁶Ru are expected to enhanced by collective neutrino oscillations in more proton-rich and slower gas flows.