New Phenomena in Neutrino Physics

In this thesis, we discuss two new concepts in neutrino physics: The neutrino Mössbauer effect and non-standard neutrino interactions. We show that neutrinos emitted and absorbed in recoil-free processes (Mössbauer neutrinos) can oscillate in spite of their near monochromaticity. We support this statement by quantum mechanical wave packet arguments and by a quantum field theoretical (QFT) calculation of the combined rate of Mössbauer neutrino emission, propagation and absorption. The QFT approach does not require any a priori assumptions on the neutrino wave function, and it allows us to include a realistic treatment of the different mechanisms leading to broadening of the emission and absorption lines. In the second part of this work, we study the phenomenology of non-standard neutrino interactions (NSI). We classifying the allowed NSI operators according to their impact on future oscillation experiments and present numerical results for the NSI sensitivities of reactor, superbeam and neutrino factory experiments. We point out that NSI could mimic standard oscillation effects, and might therefore lead to incorrect fit values for the oscillation parameters. For the case of the neutrino factory, we perform a detailed optimisation study to determine the optimum muon energy and detector configuration