2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/217308For the electroweak interactions, the massive neutrino perturbative kinematical procedure is developed in the massive neutrino Fock space; The perturbation expansion parameter is the ratio of the neutrino mass to its energy. This procedure, with the Pontecorvo-Maki-nakagawa-Sakata modified electroweak Lagrangian, calculates the cross-sections with the new neutrino energy projection operators in the massive neutrino Fock space, resulting in the Standard Model mass-less flavor neutrino cross-sections, plus the Lorentz non-invariant neutrino oscillation cross-sections which are proportional to the squares of neutrino masses and, as such, practically unobservable in the laboratory. This scheme reinforces the notion that the mass-less flavor neutrino can be considered as the superposition of three massive neutrinos.12 pages, 12 referencesHigh Energy Physics - Phenomenologytext