Electromagnetic Catalysis of a Neutrino Radiative decay or One More Source of Information on the Lepton Mixing Angles?

The radiative decay of ultrarelativistic massive neutrino $\nu_i \rightarrow \nu_j \gamma$ is investigated in electromagnetic fields in the framework of the Standard Model with lepton mixing. Estimates of the decay probability and ``decay cross-section'' for accelerator neutrinos of high energies in the electric field of nucleus permit one to discuss the general possibility of carrying out the neutrino experiment. Such an experiment could give unique information on mixing angles in the lepton sector of the Standard Model which would be almost independent of the specific neutrino masses.Comment: 6 pages, LaTeX, Talk given by L.A.Vassilevskaya at the XXXth Rencontres de Moriond, Electroweak Interactions and Unified Theories, Les Arcs, Savoie, France, March 11-18, 199

High-energy neutrino conversion into electron-W pair in magnetic field and its contribution to neutrino absorption

We calculate the conversion rate of high-energy neutrinos propagating in constant magnetic field into an electron-W pair (nu -> W + e) from the imaginary part of the neutrino self-energy. Using the exact propagators in constant magnetic field, the neutrino self-energy has been calculated to all order in the field within the Weinberg-Salam model. We obtain a compact formula in the limit of B << Bcr = m^2/e. We find that above the process threshold Eth \~ 2.2 10^16 (Bcr / B) eV this contribution to the absorption of neutrinos yields an asymptotic absorption length ~ 1.1 (Bcr / B)^2 (10^{16} eV / E) meters.Comment: 10 pages in RevTeX, 2 figures; published version: two typos corrected, one reference adde