261 research outputs found
High energy neutrino absorption by W production in a strong magnetic field
An influence of a strong external magnetic field on the neutrino self-energy
operator is investigated. The width of the neutrino decay into the electron and
W boson, and the mean free path of an ultra-high energy neutrino in a strong
magnetic field are calculated. A kind of energy cutoff for neutrinos
propagating in a strong field is defined.Comment: 13 pages, LaTeX, 1 EPS figure, submitted to Physics Letters
Photon decay gamma->nu anti-nu in an external magnetic field
The process of the photon decay into the neutrino - antineutrino pair in a
magnetic field is investigated. The amplitude and the probability are analysed
in the limits of relatively small and strong fields. The probability is
suppressed by a factor (G_F m^2_e)^2 as compared with the probability of the
pure electromagnetic process gamma -> e- e+. However, the process with
neutrinos could play a role of an additional channel of stellar energy-loss.Comment: 8 pages, LaTeX, typos fixed, minor modifications, version accepted to
Physics Letters
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, , , , , 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
Time-delay control for stabilization of the Shapovalov mid-size firm model
Control and stabilization of irregular and unstable behavior of dynamic systems (including chaotic processes) are interdisciplinary problems of interest to a variety of scientific fields and applications. Using the control methods allows improvements in forecasting the dynamics of unstable economic processes and offers opportunities for governments, central banks, and other policy makers to modify the behaviour of the economic system to achieve its best performance. One effective method for control of chaos and computation of unstable periodic orbits (UPOs) is the unstable delay feedback control (UDFC) approach, suggested by K. Pyragas. This paper proposes the application of the Pyragas’ method within framework of economic models. We consider this method through the example of the Shapovalov model, by describing the dynamics of a mid-size firm. The results demonstrate that suppressing chaos is capable in the Shapovalov model, using the UDFC method
PATHOGENETIC MECHANISMS AND PREVENTION OF RADIATION DAMAGE TO ORGANS AND TISSUES OF THE ORAL CAVITY
Today it has been proven that the basis of the damaging effects of radionuclides entering the body is the transfer of energy to target tissues. Such lesions, in contrast to radiation sickness resulting from external gamma irradiation, are characterized by a weak severity of the primary reaction, the early appearance of dysfunction of critical organs, a slow course of recovery processes, a more pronounced long-term pathology.
The issues of rehabilitation of children exposed to radiation in Russia began to deal with almost immediately after the Chernobyl accident. The system of special medical and preventive events which included was developed and approved: elimination of radionuclides from the child's organism, decrease of the activity of free radical processes, immunocorrective therapy, the differentiated methods of prevention of progressing of a disease and the three-level system of medical examination.
Key words: Radiation Damage, Dental Status, Oral Cavity
Graphical Analysis of the Growth Rate of National Economies by Considering the Supply Chain Strategy in 25 Countries over the Period From 2000 to 2016
The article presents the graphical analysis of economic indicators for 25 countries: GDP growth rate (%) and GDP per person employed (thousand US dollars) for the period from 1990 to 2016 by considering the supply chain strategy (SCS) and transparency. The authors carried out the decomposition of economic growth rates of selected countries according to the following factors: 1) extensive factors – the growth rate of the capital stock and the size of labor force; 2) intensive factors – RD expenditures; 3) the dynamics of foreign direct investment in the country 4) supply chain strategy. Over the past 16 years, only a few countries from the sample have shown growth of the national economy higher than the growth rates of the world economy. These are China, Turkmenistan, India, Malaysia, and Singapore (their economies grew at a rate of more than 5% per year). The most dynamic renewal of fixed assets can be observed in China, the United States and Japan. At the same time, over the past 10 years China has demonstrated an active investment policy, increasing the investment in fixed assets almost five times. China and India were countries that most actively used the size of labor force as a factor of extensive growth. Korea, Japan, Germany, USA, China and Singapore demonstrated the most dynamic growth in RD expenditures. Despite the non-monotonous dynamics of foreign direct investment in these countries, over the entire period of observation from 1990 to 2017, the United States has been the most attractive country for foreign direct investment. At the same time, the most significant growth in foreign direct investment was recorded in China and, recently, in the United Kingdom
The influence of strong magnetic field on photon-neutrino reactions
The two-photon two-neutrino interaction induced by magnetic field is
investigated. In particular the processes and
are studied in the presence of strong magnetic
field. An effective Lagrangian and partial amplitudes of the processes are
presented. Neutrino emissivities due to the reactions and are calculated taking into
account of the photon dispersion and large radiative corrections. A comparison
of the results obtained with previous estimations and another inducing
mechanisms of the processes under consideration is made.Comment: 16 pages, LATEX, 3 EPS figures, based on the talk presented at XXXI
ITEP Winter School of Physics, Moscow, Russia, February 18 - 26, 200
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