Oscillations of neutrinos produced and detected in crystals

We analyze neutrino oscillations in a thought experiment in which neutrinos are produced by electrons on target nuclei. The neutrinos are detected through charged lepton production in their collision with nuclei in detector. Both the target and the detector are assumed to be crystals. The neutrinos are described by propagators. We find that different neutrino mass eigenstates have equal energies. We reproduce the standard phase of oscillations and demonstrate that at large distance from the production point oscillations disappear.