On Nuclear Reactor Antineutrino Spectra and Fluxes

Abstract

New picture of neutrino mixing and masses explains the results of solar, atmospheric and reactor neutrino experiments. One sees the mixing of νe, νµ and ντ with 3 mass eigenstates νi . The obtained mass differences are in the mass region which is defined by known Λ-term from cosmology. Now neutrino from nuclear reactor together with neutrino from accelerators and radioactive sources are becoming a real driver of all elementary particle physics in searching the neutrinoless double beta decays and in investigation of oscillation phenomena. It is very useful instrument for searching new physics because of the fact that a nuclear reactors gives huge, isotropic and controllable flux of such unusual particles under investigation. Main obstacle to this program is poor knowledge of the energy spectra of reactor antineutrinos. It is related with difficulties of taking into account a large number of nuclear fragments, transforming into stable nuclei, in addition not all of these fragments have known characteristics