Narrow muon bundles from muon pair production in rock

We revise the process of muon pair production by high-energy muons in rock using the recently published cross-section. The three-dimensional Monte Carlo code MUSIC has been used to obtain the characteristics of the muon bundles initiated via this process. We have compared them with those of conventional muon bundles initiated in the atmosphere and shown that large underground detectors, capable of collecting hundreds of thousands of multiple muon events, can discriminate statistically muon induced bundles from conventional ones. However, we find that the enhancement of the measured muon decoherence function over that predicted at small distances, recently reported by the MACRO experiment, cannot be explained by the effect of muon pair production alone, unless its cross-section is underestimated by a factor of 3.Comment: 10 pages, 1 table, 2 figures, to be published in Physics Letters

Features of intra population variability of Medicago varia Mart. with the expressed mf-mutation on a complex qualitative characteristics

The purpose of this work was studying of features of intra population variability of a lucerne with a mf-mutation on a complex of the qualitative signs, valuable as for the forage production as well as for the pharmaceutical industr

Some ways of filling of the vascular bed of domestic animals

In this work the assessment of some methods of filling of the mammals blood channels is presented. As injection masses there were used the gelatine solution of 5%, painted with the ink by Borisevich V.B. technique and the solution consisting of Bustilat-M glue and the water in a proportion of 2:1. The conducted researches showed that the most successful, in terms of simplicity of execution, is filling of vessels with the solution consisting of Bustilat-M glue and water, as it allows with the little effort and with the smallest expenses to fill in both large and average vessel

Operator Approach to the Master Equation for the One-Step Process

Presentation of the probability as an intrinsic property of the nature leads researchers to switch from deterministic to stochastic description of the phenomena. The procedure of stochastization of one-step process was formulated. It allows to write down the master equation based on the type of of the kinetic equations and assumptions about the nature of the process. The kinetics of the interaction has recently attracted attention because it often occurs in the physical, chemical, technical, biological, environmental, economic, and sociological systems. However, there are no general methods for the direct study of this equation. Leaving in the expansion terms up to the second order we can get the Fokker-Planck equation, and thus the Langevin equation. It should be clearly understood that these equations are approximate recording of the master equation. However, this does not eliminate the need for the study of the master equation. Moreover, the power series produced during the master equation decomposition may be divergent (for example, in spatial models). This makes it impossible to apply the classical perturbation theory. It is proposed to use quantum field perturbation theory for the statistical systems (the so-called Doi method). This work is a methodological material that describes the principles of master equation solution based on quantum field perturbation theory methods. The characteristic property of the work is that it is intelligible for non-specialists in quantum field theory. As an example the Verhulst model is used because of its simplicity and clarity (the first order equation is independent of the spatial variables, however, contains non-linearity). We show the full equivalence of the operator and combinatorial methods of obtaining and study of the one-step process master equation.Comment: in Russian; in Englis

Polarization squeezing with cold atoms

We study the interaction of a nearly resonant linearly polarized laser beam with a cloud of cold cesium atoms in a high finesse optical cavity. We show theoretically and experimentally that the cross-Kerr effect due to the saturation of the optical transition produces quadrature squeezing on both the mean field and the orthogonally polarized vacuum mode. An interpretation of this vacuum squeezing as polarization squeezing is given and a method for measuring quantum Stokes parameters for weak beams via a local oscillator is developed

Entanglement and squeezing in a two-mode system: theory and experiment

We report on the generation of non separable beams produced via the interaction of a linearly polarized beam with a cloud of cold cesium atoms placed in an optical cavity. We convert the squeezing of the two linear polarization modes into quadrature entanglement and show how to find out the best entanglement generated in a two-mode system using the inseparability criterion for continuous variable [Duan et al., Phys. Rev. Lett. 84, 2722 (2000)]. We verify this method experimentally with a direct measurement of the inseparability using two homodyne detections. We then map this entanglement into a polarization basis and achieve polarization entanglement.Comment: submitted to J. Opt. B for a Special Issue on Foundations of Quantum Optic

Biological resources of natural forage grassland of the cretaceous south of the European Russia

The main objective of the made researches was assessment of territorial confinedness of economic and valuable plant species and also a status and productivity of a natural forage grassland within agrolandscapes of the cretaceous South of the European Russia (the territory of the Belgorod region). Biological and vegetable resources of the natural forage grasslands of the East part of the Belgorod region in a subband of the southern forest-steppe were studie

Ecological and biological features of phacelia tanacetifolia benth. in various ecotopes of Southern European Russia

The article contains the results of the study of the environmental and biological features of Ph. tanacetifolia in four natural and territorial complexes of the Belgorod region. In all natural-territorial complexes Ph. tanacetifolia accompanied by dominant species such as: M. albus Medik., Ch. album L., E. canadensis L., E. repens (L.) Nevski, S. pumila (Poir.) Roem. & Schult., C. xanthiifolia (Nutt.