Impact of eV-mass sterile neutrinos on neutrino-driven supernova outflows
- Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, 80805 München (Germany)
- Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching (Germany)
Motivated by recent hints for sterile neutrinos from the reactor anomaly, we study active-sterile conversions in a three-flavor scenario (2 active + 1 sterile families) for three different representative times during the neutrino-cooling evolution of the proto-neutron star born in an electron-capture supernova. In our ''early model'' (0.5 s post bounce), the ν{sub e}-ν{sub s} MSW effect driven by Δm{sup 2} = 2.35eV{sup 2} is dominated by ordinary matter and leads to a complete ν{sub e}-ν{sub s} swap with little or no trace of collective flavor oscillations. In our ''intermediate'' (2.9 s p.b.) and ''late models'' (6.5 s p.b.), neutrinos themselves significantly modify the ν{sub e}-ν{sub s} matter effect, and, in particular in the late model, νν refraction strongly reduces the matter effect, largely suppressing the overall ν{sub e}-ν{sub s} MSW conversion. This phenomenon has not been reported in previous studies of active-sterile supernova neutrino oscillations. We always include the feedback effect on the electron fraction Y{sub e} due to neutrino oscillations. In all examples, Y{sub e} is reduced and therefore the presence of sterile neutrinos can affect the conditions for heavy-element formation in the supernova ejecta, even if probably not enabling the r-process in the investigated outflows of an electron-capture supernova. The impact of neutrino-neutrino refraction is strong but complicated, leaving open the possibility that with a more complete treatment, or for other supernova models, active-sterile neutrino oscillations could generate conditions suitable for the r-process.
- OSTI ID:
- 22279721
- Journal Information:
- Journal of Cosmology and Astroparticle Physics, Vol. 2012, Issue 01; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
- Country of Publication:
- United States
- Language:
- English
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