158 research outputs found

    Polynomial Lie algebra methods in solving the second-harmonic generation model: some exact and approximate calculations

    Get PDF
    We compare exact and SU(2)-cluster approximate calculation schemes to determine dynamics of the second-harmonic generation model using its reformulation in terms of a polynomial Lie algebra supd(2)su_{pd}(2) and related spectral representations of the model evolution operator realized in algorithmic forms. It enabled us to implement computer experiments exhibiting a satisfactory accuracy of the cluster approximations in a large range of characteristic model parameters.Comment: LaTex file, 13 pages, 3 figure

    RESEARCH OF HUMAN BLOOD OPTICAL PROPERTIES WITH CONCENTRATION CHANGES OF BLOOD COMPONENTS IN TERAHERTZ FREQUENCY RANGE

    Get PDF
    Subject of Research.The paper presents the study of blood biochemical composition (bilirubin, creatinine, triglycerides, uric acid) effect on its optical properties, refractive index and absorption coefficient, in terahertz frequency range. Method. To obtain the values of the refractive index and the absorption coefficient, the method of terahertz time-domain spectroscopy was used in the transmission mode. Concentrations of total bilirubin, creatinine and triglycerides were measured in blood serum by the colorimetric method, the pseudokinetic method and the enzymatic method, respectively. The glucose level was determined in blood plasma by the enzyme method. All measurements of blood component concentrations were carried out at the Almazov National Medical Research Centre. Main Results. The optical properties of blood with various biochemical composition were obtained using terahertz time-domain spectroscopy at the frequency of 0.4THz. It is shown that the refractive indices and the absorption coefficients of blood decrease with an increase in the concentration of bilirubin and creatinine. It has also been found that with an increase in the concentration of uric acid and triglycerides, the refractive index of blood increases and the absorption coefficient of blood decreases, respectively. The correlation between the refractive index and the concentration of triglycerides and the correlation between the blood absorption coefficient and the concentration of uric acid were not revealed. Practical Relevance. The observed correlations between the concentrations of blood components and the optical properties are useful in the development of a new technique for blood analysis

    Association of Polymorphisms of Serotonin Transporter (5HTTLPR) and 5-HT2C Receptor Genes with Criminal Behavior in Russian Criminal Offenders

    Get PDF
    Background: Human aggression is a heterogeneous behavior with biological, psychological, and social backgrounds. As the biological mechanisms that regulate aggression are components of both reward-seeking and adversity-fleeing behavior, these phenomena are difficult to disentangle into separate neurochemical processes. Nevertheless, evidence exists linking some forms of ag

    Measurement of \Gamma_{ee}(J/\psi)*Br(J/\psi->e^+e^-) and \Gamma_{ee}(J/\psi)*Br(J/\psi->\mu^+\mu^-)

    Get PDF
    The products of the electron width of the J/\psi meson and the branching fraction of its decays to the lepton pairs were measured using data from the KEDR experiment at the VEPP-4M electron-positron collider. The results are \Gamma_{ee}(J/\psi)*Br(J/\psi->e^+e^-)=(0.3323\pm0.0064\pm0.0048) keV, \Gamma_{ee}(J/\psi)*Br(J/\psi->\mu^+\mu^-)=(0.3318\pm0.0052\pm0.0063) keV. Their combinations \Gamma_{ee}\times(\Gamma_{ee}+\Gamma_{\mu\mu})/\Gamma=(0.6641\pm0.0082\pm0.0100) keV, \Gamma_{ee}/\Gamma_{\mu\mu}=1.002\pm0.021\pm0.013 can be used to improve theaccuracy of the leptonic and full widths and test leptonic universality. Assuming e\mu universality and using the world average value of the lepton branching fraction, we also determine the leptonic \Gamma_{ll}=5.59\pm0.12 keV and total \Gamma=94.1\pm2.7 keV widths of the J/\psi meson.Comment: 7 pages, 6 figure

    Search for narrow resonances in e+ e- annihilation between 1.85 and 3.1 GeV with the KEDR Detector

    Full text link
    We report results of a search for narrow resonances in e+ e- annihilation at center-of-mass energies between 1.85 and 3.1 GeV performed with the KEDR detector at the VEPP-4M e+ e- collider. The upper limit on the leptonic width of a narrow resonance Gamma(R -> ee) Br(R -> hadr) < 120 eV has been obtained (at 90 % C.L.)

    Measurement of main parameters of the \psi(2S) resonance

    Get PDF
    A high-precision determination of the main parameters of the \psi(2S) resonance has been performed with the KEDR detector at the VEPP-4M e^{+}e^{-} collider in three scans of the \psi(2S) -- \psi(3770) energy range. Fitting the energy dependence of the multihadron cross section in the vicinity of the \psi(2S) we obtained the mass value M = 3686.114 +- 0.007 +- 0.011 ^{+0.002}_{-0.012} MeV and the product of the electron partial width by the branching fraction into hadrons \Gamma_{ee}*B_{h} = 2.233 +- 0.015 +- 0.037 +- 0.020 keV. The third error quoted is an estimate of the model dependence of the result due to assumptions on the interference effects in the cross section of the single-photon e^{+}e^{-} annihilation to hadrons explicitly considered in this work. Implicitly, the same assumptions were employed to obtain the charmonium leptonic width and the absolute branching fractions in many experiments. Using the result presented and the world average values of the electron and hadron branching fractions, one obtains the electron partial width and the total width of the \psi(2S): \Gamma_{ee} =2.282 +- 0.015 +- 0.038 +- 0.021 keV, \Gamma = 296 +- 2 +- 8 +- 3 keV. These results are consistent with and more than two times more precise than any of the previous experiments

    Π’he effect of mechanical activation on dielectric properties of ceramic ferroelectrics-relaxors PbMg1/3Nb2/3O3 and PbFe1/2Ta1/2O3

    Full text link
    УстановлСно, Ρ‡Ρ‚ΠΎ высокоэнСргСтичСская мСханоактивация исходных оксидов ΠΏΡ€ΠΈΠ²ΠΎΠ΄ΠΈΡ‚ ΠΊ Π·Π½Π°Ρ‡ΠΈΡ‚Π΅Π»ΡŒΠ½ΠΎΠΌΡƒ ΡƒΠΌΠ΅Π½ΡŒΡˆΠ΅Π½ΠΈΡŽ ΠΈΠ»ΠΈ Π΄Π°ΠΆΠ΅ ΠΏΠΎΠ»Π½ΠΎΠΌΡƒ подавлСнию частотного сдвига максимума диэлСктричСской проницаСмости ΠΊΠ΅Ρ€Π°ΠΌΠΈΠΊ сСгнСтоэлСктриков-рСлаксоров PbMg1/3Nb2/3O3 ΠΈ PbFe1/2Ta1/2O3, спСчСнных ΠΈΠ· смСси этих оксидов.High-energy mechanical activation of the starting oxides was found to reduce dramatically or even suppress the frequency shift of the dielectric permittivity maximum of ceramic ferroelectrics-relaxors PbMg1/3Nb2/3O3 and PbFe1/2Ta1/2O3 sintered from the mixture of these oxides.Π Π°Π±ΠΎΡ‚Π° Π²Ρ‹ΠΏΠΎΠ»Π½Π΅Π½Π° ΠΏΡ€ΠΈ ΠΏΠΎΠ΄Π΄Π΅Ρ€ΠΆΠΊΠ΅ Российского Π€ΠΎΠ½Π΄Π° Π€ΡƒΠ½Π΄Π°ΠΌΠ΅Π½Ρ‚Π°Π»ΡŒΠ½Ρ‹Ρ… ИсслСдований (Π³Ρ€Π°Π½Ρ‚ 17-03-01293_a) ΠΈ ΠŸΡ€ΠΎΠ΅ΠΊΡ‚Π½ΠΎΠΉ части Госзадания ΠœΠΈΠ½ΠΎΠ±Ρ€Π½Π°ΡƒΠΊΠΈ β„– 3.1649.2017/ПЧ

    The MAJORANA DEMONSTRATOR for 0Ξ½Ξ²Ξ²: Current Status and Future Plans

    Get PDF
    The MAJORANA DEMONSTRATOR will search for neutrinoless-double-beta decay (0Ξ½Ξ²Ξ²) in 76Ge, while establishing the feasibility of a future tonne-scale germanium-based 0Ξ½Ξ²Ξ² experiment, and performing searches for new physics beyond the Standard Model. The experiment, currently under construction at the Sanford Underground Research Facility in Lead, SD, will consist of a pair of modular high-purity germanium detector arrays housed inside of a compact copper, lead, and polyethylene shield. Through a combination of strict materials qualifications and assay, low-background design, and powerful background rejection techniques, the Demonstrator aims to achieve a background rate in the 0Ξ½Ξ²Ξ² region of interest (ROI) of no more than 3 counts in the 0Ξ½Ξ²Ξ²-decay ROI per tonne of target isotope per year (cnts/(ROI-t-y)). The current status of the Demonstrator is discussed, as are plans for its completion

    A Dark Matter Search with MALBEK

    Get PDF
    The Majorana Demonstrator is an array of natural and enriched high purity germanium detectors that will search for the neutrinoless double-beta decay of 76Ge and perform a search for weakly interacting massive particles (WIMPs) with masses below 10 GeV. As part of the Majorana research and development efforts, we have deployed a modified, low-background broad energy germanium detector at the Kimballton Underground Research Facility. With its sub-keV energy threshold, this detector is sensitive to potential non-Standard Model physics, including interactions with WIMPs. We discuss the backgrounds present in the WIMP region of interest and explore the impact of slow surface event contamination when searching for a WIMP signal
    • …
    corecore