839 research outputs found

    Extension of the Nambu--Jona-Lasinio model at high densities and temperatures by using an implicit regularization scheme

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    Traditional cutoff regularization schemes of the Nambu--Jona-Lasinio model limit the applicability of the model to energy-momentum scales much below the value of the regularizing cutoff. In particular, the model cannot be used to study quark matter with Fermi momenta larger than the cutoff. In the present work an extension of the model to high temperatures and densities recently proposed by Casalbuoni, Gatto, Nardulli, and Ruggieri is used in connection with an implicit regularization scheme. This is done by making use of scaling relations of the divergent one-loop integrals that relate these integrals at different energy-momentum scales. Fixing the pion decay constant at the chiral symmetry breaking scale in the vacuum, the scaling relations predict a running coupling constant that decreases as the regularization scale increases, implementing in a schematic way the property of asymptotic freedom of quantum chromodynamics. If the regularization scale is allowed to increase with density and temperature, the coupling will decrease with density and temperature, extending in this way the applicability of the model to high densities and temperatures. These results are obtained without specifying an explicit regularization. As an illustration of the formalism, numerical results are obtained for the finite density and finite temperature quark condensate, and to the problem of color superconductivity at high quark densities and finite temperature.Comment: 7 pages, 5 eps figures - in version 3, substantial changes in text, results and conclusions unchanged. To be published in Phys. Rev.

    Body composition evaluated by skinfolds, bioimpedance and body mass index in adults

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    El objetivo de este estudio fue comparar la composición corporal por pliegues cutáneos (DC) por bioimpedancia eléctrica(BIA) y el índice de masa corporal(IMC). Se hizo un trabajo de campo con 153 militares usando los siguientes equipos: balanza Wiso; estadiómetro WCS; adipómetro Cescorf científico y Malton BF-900 para bioimpedancia eléctrica. La densidad corporal se consiguió por la ecuación de Jackson&Pollock y la clasificación delporcentaje de grasa corporal siguiendo Pollock&Wilmore. Para verificar la correlación se usó el test de Spearman. Los resultados promedios (± desviación estándar) hallados para edad, peso, estatura e IMC, fueron: 19 años (±1,8 años), 70,9Kg (±9,55), 1,74 metros (±0.06) y 23,9 kg/m² (±2,76) respectivamente. El porcentaje de grasa corporal por DC y BIA fueron respectivamente 12,78 (±5,45); 16,29 (±4,02). Concluí que la composición corporal por el método de DC, BIA e IMC presentó datos que se correlacionan, siendo que el uso de la bioimpedancia fue más indicada en grupos cuyo porcentaje de grasa corporal variaba entre 18-20%.The aim of this study was to compare body composition by skinfold thickness (DC) by bioelectrical impedance analysis (BIA) and body mass index (BMI). Research was carried out with 153 soldiers with the equipment: balance Wiso; WCS stadiometer; adipometer Cescorf Malton scientific and BF-900 to bioelectrical impedance analysis. Body density was obtained by the equation of Jackson&Pollock and classification of the percentage of fat by following Pollock&Wilmore. To check the correlation was used Spearman's test. The average results (±standard deviation) found for age, weight, height and BMI were: 19 years (±1.8years), 70.9 kg (±9.55), 1.74 meters (±0.06) and 23.9 kg/m² (±2.76), respectively. The fat percentage by BIA and DC were respectively 12.78 (±5.45) and 16.29 (±4.02). Concluded that body composition by the method of DC, BIA and BMI have data that correlate, and the use of bioimpedance was indicated in most groups whose fat percentage ranged around 18-20%.Gracias CAPES para la inversión financiera en forma de beca en el Programa de Posgrado en Ingeniería Eléctrica e Informática Industrial (CPGEI) de la Universidad Tecnológica Federal de Paraná (UTFPR)

    Computing the Effective Hamiltonian of Low-Energy Vacuum Gauge Fields

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    A standard approach to investigate the non-perturbative QCD dynamics is through vacuum models which emphasize the role played by specific gauge field fluctuations, such as instantons, monopoles or vortexes. The effective Hamiltonian describing the dynamics of the low-energy degrees of freedom in such approaches is usually postulated phenomenologically, or obtained through uncontrolled approximations. In a recent paper, we have shown how lattice field theory simulations can be used to rigorously compute the effective Hamiltonian of arbitrary vacuum models by stochastically performing the path integral over all the vacuum field fluctuations which are not explicitly taken into account. In this work, we present the first illustrative application of such an approach to a gauge theory and we use it to compute the instanton size distribution in SU(2) gluon-dynamics in a fully model independent and parameter-free way.Comment: 10 pages, 4 figure

    Dual Superconductors and SU(2) Yang-Mills

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    We propose that the SU(2) Yang-Mills theory can be interpreted as a two-band dual superconductor with an interband Josephson coupling. We discuss various consequences of this interpretation including electric flux quantization, confinement of vortices with fractional flux, and the possibility that a closed vortex loop exhibits exotic exchange statistics

    A model for QCD ground state with magnetic disorder

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    We explore an ansatz for the QCD vacuum in the Coulomb gauge that describes gauge field fluctuations in presence of a weakly interacting gas of abelian monopoles. Such magnetic disorder leads to long-range correlations which are manifested through the area law for the Wilson loop. In particular we focus on the role of the residual monopole-monopole interactions in providing the mechanism for suppression of the gluon propagator at low-momenta which also leads to low momentum enhancement in the ghost propagator.Comment: 6 pages, 1 figur

    Self-consistent symmetries in the proton-neutron Hartree-Fock-Bogoliubov approach

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    Symmetry properties of densities and mean fields appearing in the nuclear Density Functional Theory with pairing are studied. We consider energy functionals that depend only on local densities and their derivatives. The most important self-consistent symmetries are discussed: spherical, axial, space-inversion, and mirror symmetries. In each case, the consequences of breaking or conserving the time-reversal and/or proton-neutron symmetries are discussed and summarized in a tabulated form, useful in practical applications.Comment: 26 RevTex pages, 1 eps figure, 9 tables, submitted to Physical Review

    БУХГАЛТЕРСЬКИЙ ОБЛІК ФІНАНСОВИХ РЕЗУЛЬТАТІВ ЯК ПЕРЕДУМОВА ПОПЕРЕДЖЕННЯ БАНКРУТСТВА ПІДПРИЄМСТВА

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    This paper analyzes the analyzes of the dynamics of the financial results of enterprises, the influence of the factors leading to reduced solvency of domestic enterprises, the necessity of timeliness of financial information as a prerequisite to avoid bankruptcy.Amidst uncertain economic environment one gives much attentionto the bankruptcy issue because many domestic businesses are in crisis or bankruptcy. This is due to the financial failure of the company to overcome the economic crisis. The increasing number of bankrupt enterprises is influenced by most companies, which work with borrowed funds being insolvent and unable to fulfill their obligations not only to suppliers, but also to major creditors.В статье проанализированы аналитическую информацию о динамике финансового результата предприятий, определено влияние факторов, приводящих к снижению платежеспособности отечественных предприятий, обоснована необходимость своевременности предоставления бухгалтерской информации как предпосылки избежания банкротства предприятия.В статті проаналізовано аналітичну інформацію щодо динаміки фінансового результату підприємств, визначено вплив факторів, що призводять до зниження платоспроможності вітчизняних підприємств, обґрунтовано необхідність своєчасності надання бухгалтерської інформації як передумови уникнення банкрутства підприємства

    Recent data to the jumping plant-lice fauna of Hungary (Hemiptera: Psylloidea)

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    Authors made regular insect collections between 2010 and 2017, especially on ornamental trees and shrubs, on streets, parks, in city greenery, forests, botanical gardens and private gardens, in various localities of Hungary. Trioza soniae Rapisarda, 1994 and Trioza scottii Löw, 1880 are reported for the first time in Hungary. New host, locality and habitat data are given

    Interactions of multi-quark states in the chromodielectric model

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    We investigate 4-quark (qqqˉqˉqq\bar{q}\bar{q}) systems as well as multi-quark states with a large number of quarks and anti-quarks using the chromodielectric model. In the former type of systems the flux distribution and the corresponding energy of such systems for planar and non-planar geometries are studied. From the comparison to the case of two independent qqˉq\bar{q}-strings we deduce the interaction potential between two strings. We find an attraction between strings and a characteristic string flip if there are two degenerate string combinations between the four particles. The interaction shows no strong Van-der-Waals forces and the long range behavior of the potential is well described by a Yukawa potential, which might be confirmed in future lattice calculations. The multi-quark states develop an inhomogeneous porous structure even for particle densities large compared to nuclear matter constituent quark densities. We present first results of the dependence of the system on the particle density pointing towards a percolation type of transition from a hadronic matter phase to a quark matter phase. The critical energy density is found at ϵc=1.2GeV/fm3\epsilon_c = 1.2 GeV/fm^3.Comment: 19 pages, 40 eps-figures, RevTex 4, v2: typos correcte
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