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. In that case different neutrino mass eigenstates have equal energies. We reproduce the standard phase of oscillations for not very large distances and demonstrate that at very large distances from the production point oscillations disappear due to the neutrino energy dispersion.