The radiative decay of a high energy neutrino in the Coulomb field of a nucleus

In the framework of the Standard Model with lepton mixing the radiative decay $\nu_i \rightarrow \nu_j \gamma$ of a neutrino of high ($E_\nu \sim 100 \, GeV$) and super-high ($E_\nu \ge 1 \, TeV$) energy is investigated in the Coulomb field of a nucleus. Estimates of the decay probability and ``decay cross-section'' for neutrinos of these energies in the electric field of a nucleus permit one to discuss the general possibility of carrying out a neutrino experiment, subject to the condition of availability in the future of a beam of neutrinos of these high energies. Such an experiment could give unique information on mixing angles in the lepton sector of the Standard Model which would be independent of the specific neutrino masses if only the threshold factor ($1 - m_j^4 / m_i^4$) was not close to zero. (Published in Phys.Lett.B 323 (1994) 179).Comment: 5 pages, LaTeX, Yaroslavl, Yaroslavl State University preprint YARU-HE-93/0

Electromagnetic Catalysis of the Radiative Decay of the Axion

The radiative decay of the axion $a \to \gamma \gamma$ is investigated in an external electromagnetic field in DFSZ model in which axion couples to both quarks and leptons at tree level. The decay probability is strongly catalyzed by the external field, namely, the field removes the main suppression caused by the smallness of the axion mass.Comment: Minor revision, references added, to be published in Phys.Lett.

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

Growth specifics and productivity of home and introduced artificial tree species plantations

The results of the analysis of growth rates and production of artificial plantations of local and introduced tree species are presente d. Brief information about the forests introduction in Belarus in the historical aspect is reported. Characteristics of research facilities located on the territory of the Republican biological reserve “Prylu ky” are given. All properties are in close proximity to each other in identical conditions of habitat (type of forest growth conditions D2 Kislichnaya series of forest types, soil, sod-pale-podzolic loamy medium podzolennaya, a powerful loess). The studied plantations ranged 70 to 106 years, which allows you to make objective conclusions about the success of their growth and formation. Analysis of plantation growth rates shows that hi gh productivity is characterized by 106 years old plantation of European larch and 80 years old culture of Douglas Fir (stem wood stock is respectively 695 and 740 m3/ha). Norway spruce plantations (reserv e in 71, returned more than 690 m3/ha) from the local coniferous-forest-forming species demonstrate hi gh growth rates that are not inferior to exotic species. Stocks of stem wood and the average increase in pine plantations are significantly lower (at the age of 87 respectively, 505 m 3/ha and 6.0 m3/ha per year). Pure and mixed stands of oak Northern demonstrated higher rates of growth and production compared to Quercus robur tree stands

Plasma influence on the neutrino - electron processes in a strong magnetic field

An influence of the magnetized electron - positron plasma on the absorption and loss of the energy and momentum in a process of neutrino propagation is investigated. A total contribution of all crossed processes, $\nu \to \nu e^- e^+$, $\nu e^- \to \nu e^-$, $\nu e^+ \to \nu e^+$, $\nu e^- e^+ \to \nu$, is found for the first time, which appears not to depend on the chemical potential of electron-positron gas. Relatively simple expressions for the probability and mean losses of the neutrino energy and momentum are obtained, which are suitable for a quantitative analysis.Comment: 8 pages, 1 ps figure, LaTeX, uses espcrc2.sty,epsf.sty, based on the talks presented at the Xth International Baksan School "Particles and Cosmology", Baksan Valley, Kabardino Balkaria, Russia, April 19-25, 1999 and the International Workshop "Particles in Astrophysics and Cosmology: From Theory to Observation", Valencia, Spain, May 3-8, 199