SIMULATED ANALYSIS OF JET CHARGE IN PP-COLLISIONS AT THE LHC
SIMULATED ANALYSIS OF JET CHARGE IN PP-COLLISIONS AT THE LHC
I. A. Kochergin
The study of jets charge is necessary to refine the theory of fragmentation in quantum chromodynamics. Also, it can provide an opportunity for improving identification methods in high-energy particle collisions. At the same time, there is a lack of data on jets from heavy flavors. The paper analyzes the weighted charge of the jets from $b$-quarks depending on the method for determining the jet and the method for calculating the electric jets charge by software simulation using the Monte Carlo generator PYTHIA 8.2. Correlations have been established between the type of $B$-meson, type $b$ or $\bar{b}$ quark, and the electric charge of the jet at certain parameters of jet separation and calculation of its charge.
Show AbstractChange in glass K-208 morphology upon irradiation with medium-energy electrons
Change in glass K-208 morphology upon irradiation with medium-energy electrons
A. I. Ustinov
The results of AFM-researches of the glass K-208 samples are presented surfaces irradiated with electrons with energies of 20÷50 keV at a particle flux density φe = 3,0•1010 ÷ 1,0•1011 cm –2s–1. The samples were irradiated in a vacuum chamber at pressure of 10–4 Pa. Shown that changes in morphology of glass K-208 upon irradiation with medium-energy electrons occur due to electrostatic discharges, which resulted in forming microprotrusions and discharge channels, as well as due to forming of gas-filled bubbles.
Show AbstractRaman spectroscopy for monitoring the dissolution of silicon nanocrystals in model liquids and living cells
Raman spectroscopy for monitoring the dissolution of silicon nanocrystals in model liquids and living cells
D. E. Maksutova$^1$, U. A. Tsurikova$^1$, M. B. Gongalsky$^1$, Y. V. Evstratova$^{1,2}$, A. A. Kudryavtsev$^{1,2}$, L. A. Osminkina$^{1,3}$
Raman spectroscopy is an informative experimental technique for studying the properties of both solid-state and biological objects. In this work, the Raman scattering method was used to study the dissolution of silicon nanocrystals (nc-Si) during their incubation in phosphate buffered saline (PBS) at 37 ° C, and with BT474 human breast carcinoma cells. Aqueous suspensions of silicon nanoparticles (SiNPs) with a diameter <90 nm were obtained by grinding arrays of porous silicon nanowires. The microphotographs of scanning and transmission electron microscopy show that nanowires and SiNPs consist of small nc-Si and pores. It was shown that incubation of nanoparticles in PBS and in cells results in a low-frequency shift of the maximum and broadening of the Stokes component of the Raman spectrum of SiNPs, the appearance of a signal from the amorphous silicon phase, a decrease in the intensity, and then complete disappearance of the signal, which indicates a decrease in the size, and then a complete dissolution of nc-Si. The results presented in this work are promising for the development of biodegradable drug delivery systems based on SiNPs.
Show AbstractAsymptotics of a step-like contrast structure with a multizonal interior layer
Asymptotics of a step-like contrast structure with a multizonal interior layer
R. E. Simakov
A boundary value problem for a singularly perturbed system of two second order ODEs with different degrees of the small parameter at the second derivatives is considered. The peculiarity of the problem is that one of the two equations of the degenerate system has three disjoint roots, two of which are double, and the third is simple (single). It is proved that for sufficiently small values of a small parameter, the problem has a solution with a fast transition from one double root of the degenerate equation to another double root in a neighborhood of some interior point of the segment. A complete asymptotic expansion of this solution is constructed and substantiated. It differs qualitatively from the well-known expansion in the case when all the roots of the degenerate equation are simple. In particular, the expansion is carried out not in integer but in fractional powers of the small parameter, the boundary layer variables have a different scale, and the transition layer turns out to be eight-zone.
Show AbstractFiltration and rheological characteristics of low-permeability reservoir rocks when modeling directional unloading method
Filtration and rheological characteristics of low-permeability reservoir rocks when modeling directional unloading method
V. I. Karev, Yu. F. Kovalenko, V. V. Khimulia
This work is devoted to the study of rheological, deformation and filtration properties of low-permeability rocks of Achimov deposits of the Urengoy gas condensate field using the directional unloading method. As part of the study, physical modeling of the real stresses in the vicinity of the well was carried out when implementing the directional unloading method. Experiments were conducted by using the unique facility, Triaxial Independent Load Test System of the Institute for Problems in Mechanics of the Russian Academy of Sciences. Modeling was carried out for two types of bottomhole design: an open hole and a perforation tip in a cased hole. The dependence of the filtration properties of rocks on the type of stress-strain state is shown; conclusions are drawn about the nature of creep. The values of pressure drawdown, which leads to an increase in the permeability, are determined. The results obtained indicate that the directional unloading method can be successfully applied to wells drilled in the Achimov deposits.
Show AbstractCharacteristics of a quasi-stationary pulsating transverse-longitudinal discharge in high-speed propane-air flows
Characteristics of a quasi-stationary pulsating transverse-longitudinal discharge in high-speed propane-air flows
I. K. Nesterenko, K. N. Kornev, A. A. Logunov, V. M. Shibkov
The paper considers the prospects of using a quasi-stationary pulsating discharge to control the process of supersonic combustion of hydrocarbon fuels. The discharge characteristics have been obtained experimentally under conditions of subsonic and supersonic air flow. Supersonic steady combustion of propane in expanding aerodynamic channels of various configurations has been implemented. The results obtained confirm the efficiency of using low-temperature plasma in supersonic plasma aerodynamics.
Show AbstractStudy of the influence of dynamic and thermal characteristics of the atmospheric boundary layer on atmospheric air pollution in the Moscow metropolis
Study of the influence of dynamic and thermal characteristics of the atmospheric boundary layer on atmospheric air pollution in the Moscow metropolis
K. V. Rodina, E. G. Semutnikova
This article focuses on assessing the impact of wildfires and adverse weather conditions on air pollution in Moscow. The article examines in detail the case of aerosol pollution of the smoky atmosphere of the Moscow region in July 2016. The main indicators of wildfire investigated in this work are particulate matter PM10 and PM2.5. Calculations of the main statistical characteristics of PM10 and PM2.5 concentrations are presented: the average value, median and mode and pair correlation coefficients separately for PM10 and PM2.5 between different stations and between PM10 and PM2.5 at one station for the entire period of 2016 and 2018 as well as for the smoke period in July 2016 and the period with bad weather conditions in September 2018. The diurnal course under smoke is analyzed in comparison with the typical course in the warm period and in the bad weather conditions. Based on the intra-day dynamics of PM10 and PM2.5 concentrations in July 2016 and September 2018 the dependence of pollution on the thermal stratification of the atmospheric boundary layer is considered. The dependence of aerosol concentrations on the wind speed in the atmospheric boundary layer is analyzed.
Show AbstractОсобенности 2D-бифуркаций для структур с квантовыми точками из коллоидного золота, обладающих свойствами метаматериала
Особенности 2D-бифуркаций для структур с квантовыми точками из коллоидного золота, обладающих свойствами метаматериала
V. C. Zhukovsky$^1$, V. D. Krevchik$^2$, M. B. Semenov$^2$, P. V. Krevchik$^2$, D. A. Saburova$^2$, I. M. Semenov$^2$, A. D. Smirnova$^2$, I. A. Rubtsov$^2$, I. S. Antonov$^2$
In framework of the 2D - dissipative tunneling theory in approximation of a rarefied gas of the «instanton - antiinstanton pairs» at a finite temperature under the conditions of an external electric field, the features of tunneling transport for planar structures with quantum dots (QDs) from colloidal gold, that have metamaterial properties, have been studied. It was experimentally shown that, depending on the positioning of the cantilever needle of a combined atomic force and scanning tunneling microscope (AFM / STM), either above a single quantum dot or between two neighboring quantum dots, either a single or double effect of 2D tunneling bifurcations have been observed, respectively. It is such a double bifurcation regime, as our theoretical model has shown, that is associated with the manifestation of the metamaterial properties by the structure under study. A convincing qualitative agreement between the experimental I – V characteristics and the field dependence of the 2D - dissipative tunneling probability in the two studied modes, taking into account the observed quantum beats in the vicinity of the 2D bifurcation points, has been obtained.
Show AbstractHamiltonian constrained formalism for the general field theories with unfree gauge symmetry
Hamiltonian constrained formalism for the general field theories with unfree gauge symmetry
V. A. Abakumova, S. L. Lyakhovich
We consider constrained Hamiltonian formalism with any finite order of constraints for general field theory with unfree gauge symmetry. It is noticed that the redefinition of the Hamiltonian by adding constraint terms, as well as the linear combination of constraints of all generations, does not change the gauge identities, and therefore the unfree gauge symmetry transformations. The general formalism is exemplified by the model of linearized unimodular gravity, for which the triviality of a cubic vertex, proportional to the completion function of a free theory, is also demonstrated in the Hamiltonian formalism.
Show AbstractSensitive to light scalars $B\to K^*l^+l^-$ angular observables in NMSSM
Sensitive to light scalars $B\to K^*l^+l^-$ angular observables in NMSSM
A. I. Mukhaeva$^1$, A. V. Bednyakov$^{1,2}$
In this work we consider NMSSM scenarios with light (pseudo) scalars, which have masses ranging from 10 to 100 GeV. The main goal of the study is to revisit the invariant mass squared of the lepton pair q^2-dependent angular B -> K^*l^+l^- observables, which are sensitive to scalar contributions, and estimate the magnitude of the latter in the considered scenarios. In addition, prospects of experimental study of the effects are discussed.
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