ИСТИНА

A novel quantum field-theoretical approach to the description of processes passing at finite space-time intervals is discussed. It is based on the Feynman diagram technique in the coordinate representation supplemented by the modified rules of passing to the momentum representation, which reflect the experimental situation at hand. Effectively, it leads to a modification of the Feynman propagator of the virtual neutrino mass eigenstates in the momentum representation, while all the other Feynman rules in this representation are kept intact. The T2K experimental setting is considered and the oscillation fading out due to momentum distribution of the initial particles is taken into account. The obtained results reproduce the predictions of the standard description and confirm that the far detector position corresponds to the first minimum for muon production probability and the first maximum for electron production probability.