title: Flavor oscillations in the supernova hot bubble region: nonlinear effects of neutrino background.
abstract: The neutrino flux close to a supernova core contributes substantially to neutrino refraction so that flavor oscillations become a nonlinear phenomenon. One unexpected consequence is efficient flavor transformation for antineutrinos in a region where only neutrinos encounter a Mikheyev-Smirnov-Wolfenstein resonance or vice versa. Contrary to previous studies we find that in the neutrino-driven wind the electron fraction Y(e) always stays below 0.5, corresponding to a neutron-rich environment as required by r-process nucleosynthesis. The relevant range of masses and mixing angles includes the region indicated by LSND, but not the atmospheric or solar oscillation parameters.
authors.affiliation: Max-Planck-Institut für Physik, Werner-Heisenberg-Institut, Föhringer Ring 6, 80805 Munich, Germany.
authors.forename: Sergio
authors.initials: S
authors.lastname: Pastor
authors.forename: Georg
authors.initials: G
authors.lastname: Raffelt