Some Unsettled Questions in the Problem of Neutrino Os- cillations. Mechanisms of Neutrino Oscillations

In the modern theory of neutrino oscillations constructed in the framework of the theory particle physics there appears three types of neutrino transitions (oscillations). Then, in order to solve the question of which type of neutrino transitions (oscillations) are realized in nature, in experiments, it is necessary to study profile of neutrino transitions in dependence on distances for determination lengths and angle mixings. At present it is presumed that Dirac and Majorana neutrino oscillations can be realized. It is shown that we cannot put Majorana neutrinos in the standard weak interactions theory without violation of the gauge invariance. Also is shown that the mechanism of resonance enhancement of neu-trino oscillations in matter cannot be realized without violation of the law of energy-momentum conservation. Then, it is obvious that there can be only real-ized transitions (oscillations) between Dirac neutrinos with different flavors. 1