Electromagnetic catalysis of the radiative transitions of ν i → ν j γ type in the field of an intense monochromatic wave

Electromagnetic catalysis of the radiative transitions of ν i → ν j γ type in the field of an intense monochromatic wave Abstract The radiative decay of the massive neutrino ν i → ν j γ in a circularly polarized electromagnetic wave is investigated within the Standard theory with lepton mixing. The decay probability in the wave field does not contain a threshold factor ∼ (1 − m i /m j) as opposed to the decay probability in a vacuum or in a constant uniform external field. The phenomenon of the gigantic enhancement (∼ 10 33) of the neutrino decay probability in external wave field is discovered. The probability of the photon splitting into the neutrino pair is obtained.