Active–Sterile Neutrino Oscillations in Neutrino-driven Winds: Implications for Nucleosynthesis.

A protoneutron star produced in a core-collapse supernova (CCSN) drives a wind by its intense neutrino emission. We implement active–sterile neutrino oscillations in a steady-state model of this neutrino-driven wind to study their effects on the dynamics and nucleosynthesis of the wind in a self-consistent manner. Using vacuum mixing parameters indicated by some experiments for a sterile νs of ∼1 eV in mass, we observe interesting features of oscillations due to various feedback. For the higher νs mass values, we find that oscillations can reduce the mass-loss rate and the wind velocity by a factor of ∼1.6–2.7 and change the electron fraction critical to nucleosynthesis by a significant to large amount. In the most dramatic cases, oscillations shift nucleosynthesis from dominant production of 45Sc to that of 86Kr and 90Zr during the early epochs of the CCSN evolution. [ABSTRACT FROM AUTHOR]