Solar neutrino spectrum, sterile neutrinos and additional radiation in the Universe
Dec, 2010Citations per year
Abstract: (arXiv)
Recent results from the SNO, Super-Kamiokande and Borexino experiments do not show the expected upturn of the energy spectrum of events (the ratio ) at low energies. At the same time, cosmological observations testify for possible existence of additional relativistic degrees of freedom in the early Universe: . These facts strengthen the case of very light sterile neutrino, , with eV, which mixes weakly with the active neutrinos. The mixing in the mass eigenstate characterized by can explain an absence of the upturn. The mixing of in the eigenstate with leads to production of via oscillations in the Universe and to additional contribution before the big bang nucleosynthesis and later. Such a mixing can be tested in forthcoming experiments with the atmospheric neutrinos as well as in future accelerator long baseline experiments. It has substantial impact on conversion of the supernova neutrinos.Note:
- 27 pages, LaTeX, 14 eps figures, 3 figures and additional considerations added
- 14.60.Pq
- neutrino: sterile
- neutrino: atmosphere
- neutrino: supernova
- neutrino: spectrum
- neutrino: solar
- nucleosynthesis: big bang
- accelerator
- KAMIOKANDE
- Borexino
References(40)
Figures(14)