Увійти

Готові списки джерел за темами / Gluons / Статті в журналах

Щоб переглянути інші типи публікацій з цієї теми, перейдіть за посиланням: Gluons.

Статті в журналах з теми "Gluons"

Автор: Grafiati

Опубліковано: 4 червня 2021

Оновлено: 6 вересня 2023

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями

Оберіть тип джерела:

Ознайомтеся з топ-50 статей у журналах для дослідження на тему "Gluons".

Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.

Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.

Переглядайте статті в журналах для різних дисциплін та оформлюйте правильно вашу бібліографію.

1

Wolschin, Georg. "Aspects of Relativistic Heavy-Ion Collisions." Universe 6, no. 5 (April 30, 2020): 61. http://dx.doi.org/10.3390/universe6050061.

Повний текст джерела

Анотація:

The rapid thermalization of quarks and gluons in the initial stages of relativistic heavy-ion collisions is treated using analytic solutions of a nonlinear diffusion equation with schematic initial conditions, and for gluons with boundary conditions at the singularity. On a similarly short time scale of t ≤ 1 fm/c, the stopping of baryons is accounted for through a QCD-inspired approach based on the parton distribution functions of valence quarks, and gluons. Charged-hadron production is considered phenomenologically using a linear relativistic diffusion model with two fragmentation sources, and a central gluonic source that rises with ln 3 ( s N N ) . The limiting-fragmentation conjecture that agrees with data at energies reached at the Relativistic Heavy-Ion Collider (RHIC) is found to be consistent with Large Hadron Collider (LHC) data for Pb-Pb at s N N = 2.76 and 5.02 TeV. Quarkonia are used as hard probes for the properties of the quark-gluon plasma (QGP) through a comparison of theoretical predictions with recent CMS, ALICE and LHCb data for Pb-Pb and p-Pb collisions.

Стилі APA, Harvard, Vancouver, ISO та ін.

2

GEORGIOU, GEORGE, and GEORGE SAVVIDY. "PRODUCTION OF NON-ABELIAN TENSOR GAUGE BOSONS TREE AMPLITUDES AND BCFW RECURSION RELATION." International Journal of Modern Physics A 26, no. 15 (June 20, 2011): 2537–55. http://dx.doi.org/10.1142/s0217751x1105350x.

Повний текст джерела

Анотація:

The BCFW recursion relation is used to calculate tree-level scattering amplitudes in generalized Yang–Mills theory and, in particular, four-particle amplitudes for the production rate of non-Abelian tensor gauge bosons of arbitrary high spin in the fusion of two gluons. The consistency of the calculations in different kinematical channels is fulfilled when all dimensionless cubic coupling constants between vector bosons and high spin non-Abelian tensor gauge bosons are equal to the Yang–Mills coupling constant. We derive a generalization of the Parke–Taylor formula in the case of production of two tensor gauge bosons of spin-s and N gluons (jets). The expression is holomorphic in the spinor variables of the scattered particles, exactly as the MHV gluon amplitude is, and reduces to the gluonic MHV amplitude when s = 1.

Стилі APA, Harvard, Vancouver, ISO та ін.

3

Cho, Y. M. "Abelian Decomposition and Monopole Condensation in QCD." EPJ Web of Conferences 182 (2018): 02029. http://dx.doi.org/10.1051/epjconf/201818202029.

Повний текст джерела

Анотація:

We demonstrate the monopole condensation in QCD using the Abelian decomposition. The Abelian decomposition decomposes the gluons to the color neutral binding gluons (the neurons and the monopoles) and the colored valence gluons (the chromons), and shows that QCD can be viewed as the restricted QCD (RCD) made of the binding gluons which has the chromons as colored source. This simplifies the QCD dynamics greatly. In the perturbative regime this decomposes the gluon propagater to the neuron propagaters and the chromon propagaters, and simplifies the Feynman diagram. In the non-perturbative regime this allows us to calculate the QCD effective potential gauge independently, and demonstrate the monopole condensation unambiguously.

Стилі APA, Harvard, Vancouver, ISO та ін.

4

NISHIJIMA, KAZUHIKO. "CONFINEMENT OF QUARKS AND GLUONS." International Journal of Modern Physics A 09, no. 21 (August 20, 1994): 3799–819. http://dx.doi.org/10.1142/s0217751x94001539.

Повний текст джерела

Анотація:

It is proved without recourse to any approximation that quarks and gluons are confined simultaneously when the anomalous dimension of the gluon field is negative in the weak coupling limit. The proof is based on the BRS invariance of quantum chromodynamics and the Oehme–Zimmermann superconvergence relation for the spectral function of the gluon field.

Стилі APA, Harvard, Vancouver, ISO та ін.

5

Morreale, Astrid, and Farid Salazar. "Mining for Gluon Saturation at Colliders." Universe 7, no. 8 (August 23, 2021): 312. http://dx.doi.org/10.3390/universe7080312.

Повний текст джерела

Анотація:

Quantum chromodynamics (QCD) is the theory of strong interactions of quarks and gluons collectively called partons, the basic constituents of all nuclear matter. Its non-abelian character manifests in nature in the form of two remarkable properties: color confinement and asymptotic freedom. At high energies, perturbation theory can result in the growth and dominance of very gluon densities at small-x. If left uncontrolled, this growth can result in gluons eternally growing violating a number of mathematical bounds. The resolution to this problem lies by balancing gluon emissions by recombinating gluons at high energies: phenomena of gluon saturation. High energy nuclear and particle physics experiments have spent the past decades quantifying the structure of protons and nuclei in terms of their fundamental constituents confirming predicted extraordinary behavior of matter at extreme density and pressure conditions. In the process they have also measured seemingly unexpected phenomena. We will give a state of the art review of the underlying theoretical and experimental tools and measurements pertinent to gluon saturation physics. We will argue for the need of high energy electron-proton/ion colliders such as the proposed EIC (USA) and LHeC (Europe) to consolidate our knowledge of QCD knowledge in the small x kinematic domains.

Стилі APA, Harvard, Vancouver, ISO та ін.

6

Peláez, Marcela. "Massive gluons in Curci-Ferrari model for describing infrared QCD." EPJ Web of Conferences 274 (2022): 02002. http://dx.doi.org/10.1051/epjconf/202227402002.

Повний текст джерела

Анотація:

At large energy quarks and gluons behave as free particles and therefore the standard perturbative analysis of QCD gives very good results. However, this is not the situation in the low energy regime of QCD which is generally treated with nonperturbative methods. In spite of this, lattice simulations observe that the expansion parameter is not large in the gluonic sector. In particular, the coupling constant do not reach a Landau pole in the infrared as it is expected by standard perturbation theory. On top of this, lattice simulations find that the gluon propagator behaves as a massive propagator in the infrared. Motivated by these observations we use a model that includes a mass for the gluon (Curci-Ferrari) that can reproduce the same kind of behaviour for the gluon propagator and also a similar expansion parameter as the one found by the lattice. In this proceeding we show some of the results of quenched correlation functions obtained by using that small parameter for computing one and two loops corrections. At the end, we compare them with lattice data obtaining very good results.

Стилі APA, Harvard, Vancouver, ISO та ін.

7

Kokoulina, Elena, Andrey Kutov, Vladimir Nikitin, Vasilii Riadovikov, and Alexander Vorobiev. "A look at hadronization via high multiplicity." EPJ Web of Conferences 204 (2019): 06009. http://dx.doi.org/10.1051/epjconf/201920406009.

Повний текст джерела

Анотація:

Multiparticle production is studied experimentally and theoretically in QCD that describes interactions in the language of quarks and gluons. In the experiment the real hadrons are registered. Various phenomenological models are used for transfer from quarks and gluons to observed hadrons. In order to describe the high multiplicity region, we have developed a gluon dominance model (GDM). It represents a convolution of two stages. The first stage is described as a part of QCD. For the second one (hadronization), the phenomenological model is used. To describe hadronization, a scheme has been proposed, consistent with the experimental data in the region of its dominance. Comparison of this model with data on e+e- annihilation over a wide energy interval (up to 200 GeV) has confirmed the fragmentation mechanism of hadronization, the development of the quark-gluon cascade with energy increase and domination of bremsstrahlung gluons. The description of topological cross sections in pp collisions within GDM testifies that in hadron collisions the mechanism of hadronization is being replaced by the recombination one. At that point, gluons play an active role in the multiparticle production process, and valence quarks are passive. They stay in the leading particles, and only the gluon splitting is responsible for the region of high multiplicity. GDM with inclusion of intermediate quark charged topologies describes topological cross sections in pp̅ annihilation and explains initial linear growth in the region of negative values of a secondary correlative momentum vs average pion multiplicity with increasing of energy. The proposed hadronization scheme can describe the basic processes of multiparticle production.

Стилі APA, Harvard, Vancouver, ISO та ін.

8

MARTYNOV, M. V., and A. D. SMIRNOV. "COLORED SCALAR PARTICLES PRODUCTION IN pp-COLLISIONS AND POSSIBLE MASS LIMITS FOR SCALAR GLUONS FROM FUTURE LHC DATA." Modern Physics Letters A 23, no. 34 (November 10, 2008): 2907–13. http://dx.doi.org/10.1142/s0217732308028375.

Повний текст джерела

Анотація:

Cross sections of the colored scalar particle production in pp-collisions are calculated and differential and total cross sections of the corresponding parton subprocesses are obtained. The total cross section of scalar gluon production in pp-collisions at the LHC is estimated and the dominant decays of scalar gluons are discussed. The production cross section of scalar gluons F with masses mF ≲ 1300 GeV is shown to be sufficient for the effective production of these particles at the LHC.

Стилі APA, Harvard, Vancouver, ISO та ін.

9

da SILVA, MÁRIO L. L., CÉSAR A. Z. VASCONCELLOS, and DIMITER HADJIMICHEF. "A NEW SIGNATURE FOR GLUEBALLS." International Journal of Modern Physics D 13, no. 07 (August 2004): 1399–404. http://dx.doi.org/10.1142/s0218271804005596.

Повний текст джерела

Анотація:

In this work we use a mapping technique to derive in the context of a constituent gluon model an effective Hamiltonian that involves explicit gluon degrees of freedom. We study glueballs with two gluons using the Fock–Tani formalism.

Стилі APA, Harvard, Vancouver, ISO та ін.

10

Zolghadr, Behnam. "Being and Nothingness." Australasian Journal of Logic 16, no. 3 (June 26, 2019): 68. http://dx.doi.org/10.26686/ajl.v16i3.4075.

Повний текст джерела

Анотація:

Graham Priest’s Theory of Gluons concerns the problem of unity, i.e. what makes an object into a unity? Based on his theory of Gluons, Priest gives his accounts of being and nothingness. In this paper, I will explore the relationship between nothingness and the being of the totality of every object, and then, I will try to demonstrate that, according to Gluon Theory, these two have the same properties, or in other words, nothingness is the being of the totality of every object.

Стилі APA, Harvard, Vancouver, ISO та ін.

11

CUI, J. Y., and J. M. WU. "THE BOUND STATE EQUATION FOR TWO GLUONS AND ITS SOLUTION." International Journal of Modern Physics A 14, no. 13 (May 20, 1999): 2117–32. http://dx.doi.org/10.1142/s0217751x9900107x.

Повний текст джерела

Анотація:

We derive the bound state equation for two gluons in relativistic quantum field theory, i.e. the Bethe–Salpeter (BS) equation for two gluons. To solve it, we choose the kernel as the sum of a one-gluon exchange potential, a contact interaction and a linear confining potential. Under instantaneous approximation, this BS equation is solved numerically. The spectrum and the BS wave function of the glueballs are obtained in this framework. The numerical results are in agreement with that of recent lattice calculation.

Стилі APA, Harvard, Vancouver, ISO та ін.

12

KATO, KIYOSHI, and TOMO MUNEHISA. "THREE-BODY DECAY FUNCTIONS IN QCD JETS." Modern Physics Letters A 01, no. 05 (August 1986): 345–53. http://dx.doi.org/10.1142/s0217732386000439.

Повний текст джерела

Анотація:

Jet evolution based on perturbative QCD is studied taking into account the next-to-leading-order effect. The 3-body decay functions are required to be positive to generate the jet evolution in a Monte Carlo simulation and their magnitude is to be small enough to assure the perturbative expansion. We present a description of the angular ordering which enables us to obtain decay functions for gluon→3 gluons and quark→ quark+2 gluons which are positive and of sizable magnitude.

Стилі APA, Harvard, Vancouver, ISO та ін.

13

Steinhauser, Marc, André Sternbeck, Björn Wellegehausen, and Andreas Wipf. "Spectroscopy of four-dimensional N = 1 supersymmetric SU(3) Yang-Mills theory." EPJ Web of Conferences 175 (2018): 08022. http://dx.doi.org/10.1051/epjconf/201817508022.

Повний текст джерела

Анотація:

Supersymmetric gauge theories are an important building block for extensions of the standard model. As a first step towards Super-QCD we investigate the pure gauge sector with gluons and gluinos on the lattice, in particular the low energy mass spectrum: meson-like gluinoballs, gluino-glueballs and pure glueballs. We report on some first calculations performed with clover improved Wilson fermions on rather small lattices. The supersymmetric continuum limit and particle masses are discussed and compared to predictions from effective field theory.

Стилі APA, Harvard, Vancouver, ISO та ін.

14

DA SILVA, M. L. L., D. HADJIMICHEF, and C. A. Z. VASCONCELLOS. "GLUEBALL-GLUEBALL POTENTIAL IN A CONSTITUENT GLUON MODEL." International Journal of Modern Physics: Conference Series 18 (January 2012): 211–15. http://dx.doi.org/10.1142/s2010194512008471.

Повний текст джерела

Анотація:

In this work we use a mapping technique to derive in the context of a constituent gluon model an effective Hamiltonian that involves explicit gluon degrees of freedom. We study glueballs with two gluons using the Fock-Tani formalism. In the present work we calculate the glueball-glueball potential, in the context of the constituent gluon model, with gluon interchange.

Стилі APA, Harvard, Vancouver, ISO та ін.

15

CELENZA, L. S., C. M. SHAKIN, HUI-WEN WANG, and XIN-HUA YANG. "SPACE-TIME PROPAGATION OF CONFINED GLUONS." International Journal of Modern Physics A 04, no. 15 (September 1989): 3807–18. http://dx.doi.org/10.1142/s0217751x89001539.

Повний текст джерела

Анотація:

We assume that there is gluon condensate in the zero-momentum mode in the QCD ground state. A lowest-order calculation in terms of a condensate order parameter leads to a dynamical mass for gluons via the Schwinger mechanism and a gluon propagator with no on-mass-shell singularities — that is, the gluon is a "nonpropagating mode" in the gluon condensate. We transform our momentum-space propagator into coordinate space and find that the propagator has essentially the same delta-function light-cone singularities as the free propagator. However, in contrast to a theory without confinement, we show that the propagator exhibits exponential decay, both for time-like and space-like propagation. In this manner, we obtain a space-time characterization of the confinement phenomenon in terms of an order parameter of the condensate.

Стилі APA, Harvard, Vancouver, ISO та ін.

16

Nedelko, Sergei, and Aleksei Nikolskii. "Photons as a Signal of Deconfinement in Hadronic Matter under Extreme Conditions." Physics 5, no. 2 (May 16, 2023): 547–53. http://dx.doi.org/10.3390/physics5020039.

Повний текст джерела

Анотація:

The photon production by conversion of gluons gg→γ via quark loop in the framework of the mean-field approach to the QCD (quantunm chromodynamics) vacuum is studied here. According to the domain model of QCD vacuum, the confinement phase is dominated by Abelian (anti-)self-dual gluon fields, while the deconfinement phase is characterized by a strong chromomagnetic field. In the confinement phase, photon production is impossible due to the random spacial orientation of the statistical ensemble of vacuum fields. However, the conditions of Furry theorem are not satisfied in the deconfinement phase, the conversion of gluons is nonzero and, in addition, photon distribution has a strong angular anisotropy. Thus, the photon production in the discussed process acts as one of the important features of transition in quark-gluon plasma to the deconfinement phase.

Стилі APA, Harvard, Vancouver, ISO та ін.

17

Jalilian-Marian, Jamal. "Ultra-high energy neutrino-nucleon scattering and gluon saturation." International Journal of Modern Physics E 27, no. 12 (December 2018): 1840006. http://dx.doi.org/10.1142/s0218301318400062.

Повний текст джерела

Анотація:

Ultra-high energy neutrinos are an enigma; among their many poorly understood aspects are their origins and how they interact with nucleons when they reach the Earth. Due to the hard scale ([Formula: see text]) involved in neutrino-nucleon scattering and for a large range of neutrino energies, it is appropriate to describe the target nucleon in terms of its partons — quarks and gluons — and their evolution with [Formula: see text] as governed by the Dokshitzer–Gribov–Lipatov–Altarelli–Parisi (DGLAP) evolution equations of perturbative Quantum ChromoDynamics (pQCD). Nevertheless, at the highest neutrino energies, the scattering cross-section is dominated by the contribution of small [Formula: see text] gluons of the target where one expects DGLAP evolution equations to break down due to high gluon density effects (gluon saturation). Here, we give a brief overview of gluon saturation physics in QCD and its effects on ultra-high energy neutrino-nucleon (nucleus) scattering cross-section.

Стилі APA, Harvard, Vancouver, ISO та ін.

18

CORNWALL, JOHN M. "POSITIVITY VIOLATIONS IN QCD." Modern Physics Letters A 28, no. 38 (December 4, 2013): 1330035. http://dx.doi.org/10.1142/s0217732313300358.

Повний текст джерела

Анотація:

Both lattice simulations and theoretical studies show that the spectral function of the gluon propagator of QCD (in various gauges, as well as for the gauge-invariant Pinch Technique, or PT, propagator) is not nonnegative everywhere, although it should be if it has a physical interpretation as in QED. Theory says moreover that the non-positive spectral function of the Landau-gauge or of the PT gluon propagator is further constrained to obey a superconvergence relation (the integral of the spectral function vanishes). We review the theoretical and lattice evidence for violation of positivity as well as various interpretations of this violation, and consider methods for checking superconvergence on the lattice (so far undone). The most common interpretation is that positivity violation implies confinement of gluons, so the gluon propagator does not describe processes with physical gluons. Another more direct and gauge-invariant interpretation arises from the PT: Asymptotic freedom alone demands non-positivity and superconvergence.

Стилі APA, Harvard, Vancouver, ISO та ін.

19

KOCH, P., B. MÜLLER, H. STÖCKER, and W. GREINER. "ANTIBARYON-BARYON RATIOS AS A SIGNAL FOR QUARK GLUON PLASMA FORMATION." Modern Physics Letters A 03, no. 08 (July 1988): 737–42. http://dx.doi.org/10.1142/s021773238800088x.

Повний текст джерела

Анотація:

In a previously developed non-equilibrium model for hadronization of a quark gluon plasma, we study hadronic signals for plasma formation. We find that fragmentation of gluons into quark-antiquark pairs can lead to a strong enhancement of various antibaryon to baryon ratios if a baryon-rich quark gluon plasma is formed.

Стилі APA, Harvard, Vancouver, ISO та ін.

20

BIRÓ, TAMÁS S. "MASSIVE GLUONS AND QUARK GLUON PLASMA SIGNATURES." International Journal of Modern Physics E 01, no. 01 (March 1992): 39–72. http://dx.doi.org/10.1142/s0218301392000035.

Повний текст джерела

Анотація:

The evolution of the physical picture of the quark gluon plasma from an ideal gas to a complicated interacting system is reviewed. Recent calculations of quark gluon plasma signatures are discussed which consider a nonvanishing in-medium gluon mass.

Стилі APA, Harvard, Vancouver, ISO та ін.

21

Campos, A., K. Holland, and U. J. Wiese. "Complete wetting of gluons and gluinos." Physics Letters B 443, no. 1-4 (December 1998): 338–46. http://dx.doi.org/10.1016/s0370-2693(98)01315-x.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

22

Busza, Wit, Krishna Rajagopal, and Wilke van der Schee. "Heavy Ion Collisions: The Big Picture and the Big Questions." Annual Review of Nuclear and Particle Science 68, no. 1 (October 19, 2018): 339–76. http://dx.doi.org/10.1146/annurev-nucl-101917-020852.

Повний текст джерела

Анотація:

Heavy ion collisions quickly form a droplet of quark–gluon plasma (QGP) with a remarkably small viscosity. We give an accessible introduction to how to study this smallest and hottest droplet of liquid made on Earth and why it is so interesting. The physics of heavy ion collisions ranges from highly energetic quarks and gluons described by perturbative QCD to a bath of strongly interacting gluons at lower energy scales. These gluons quickly thermalize and form QGP, while the energetic partons traverse this plasma and end in a shower of particles called jets. Analyzing the final particles in various ways allows us to study the properties of QGP and the complex dynamics of multiscale processes in QCD that govern its formation and evolution, providing what is perhaps the simplest form of complex quantum matter that we know of. Much remains to be understood, and throughout the review big open questions are encountered.

Стилі APA, Harvard, Vancouver, ISO та ін.

23

Stumpf, H. "Composite Gluons and Effective Nonabelian Gluon Dynamics in a Unified Spinor-Isospinor Preon Field Model." Zeitschrift für Naturforschung A 42, no. 3 (March 1, 1987): 213–26. http://dx.doi.org/10.1515/zna-1987-0301.

Повний текст джерела

Анотація:

The model is defined by a selfregularizing nonlinear preon field equation and all observable (elementary and non-elementary) particles are assumed to be bound (quantum) states of the fermionic preon fields. In particular electroweak gauge bosons are two-particle composites, leptons and quarks are three-particle composites, and gluons are six-particle composites. Electroweak gauge bosons, leptons and quarks and their effective interactions etc. were studied in preceding papers. In this paper gluons and their effective dynamics are discussed. Due to the complications of a six-particle bound state dynamics the formation of gluons is performed in two steps: First the effective dynamics of three-particle composites (quarks) is derived, and secondly gluons are fusioned from two quarks respectively. The resulting effective gluon dynamics is a non-abelian SU(3) dynamics, i.e. this local gauge dynamics is produced by the properties of the composites and need not be introduced in the original preon field equation. Mathematically these results are achieved by the application of functional quantum theory to the model under consideration and subsequent evaluation of weak mapping procedures, both introduced in preceding papers. PACS 11.10 Field theory. PACS 12.10 Unified field theories and models. PACS 12.35 Composite models of particles.

Стилі APA, Harvard, Vancouver, ISO та ін.

24

Ellis, John. "The discovery of the gluon." International Journal of Modern Physics A 29, no. 31 (December 20, 2014): 1430072. http://dx.doi.org/10.1142/s0217751x14300725.

Повний текст джерела

Анотація:

Soon after the postulation of quarks, it was suggested that they interact via gluons, but direct experimental evidence was lacking for over a decade. In 1976, Mary Gaillard, Graham Ross and the author suggested searching for the gluon via 3-jet events due to gluon bremsstrahlung in e+ e- collisions. Following our suggestion, the gluon was discovered at DESY in 1979 by TASSO and the other experiments at the PETRA collider.

Стилі APA, Harvard, Vancouver, ISO та ін.

25

Borisenko, O. A., and V. V. Skalozub. "On plasmon contribution to the hot A0 condensate." Journal of Physics and Electronics 27, no. 2 (December 27, 2019): 3–8. http://dx.doi.org/10.15421/331916.

Повний текст джерела

Анотація:

In SU(2) gluodynamics, the Debye gluon contribution WD(A0) to the effective action of the temporal gauge field component (we consider A0 = const) in the background Rξext is calculated at high temperaturegauge. It is shown that at A0 ≠ 0 the standard definition k0 = 0 , |k| → 0 corresponds to long distance correlations for the longitudinal in internal space gluons. The transversal gluons become screened by the A0 background field. Therefore, they give zero contributions and have to be excluded from the correlation corrections. The total effective action accounting for the one-loop, two-loop, and correct WD(A0) satisfies Nielsen’s identity that proves gauge invariance of the A0 condensation phenomenon.

Стилі APA, Harvard, Vancouver, ISO та ін.

26

CIVITARESE, O., and P. O. HESS. "MODELLING THE NON-PERTURBATIVE VACUUM OF QCD." International Journal of Modern Physics E 15, no. 06 (September 2006): 1233–42. http://dx.doi.org/10.1142/s0218301306004764.

Повний текст джерела

Анотація:

The properties of the non-perturbative vacuum of QCD are modelled within the framework of a bosonized QCD Hamiltonian. The Hamiltonian includes fermion (valence quarks and quark-antiquark pairs) and bosons (pairs of gluons) interacting via effective interactions. The couplings between these degrees of freedom are fixed from the phenomenology and the Hamiltonian is transformed into a boson basis to map quark-antiquark pairs and pairs of gluons. With these elements we calculate the parameters which define gluon and fermion condensates and compare their values with the ones obtained by applying sum rule techniques. The agreement between the results is rather good, in spite of the simplicity of the model.

Стилі APA, Harvard, Vancouver, ISO та ін.

27

TANNENBAUM, M. J. "HEAVY ION PHYSICS AT RHIC." International Journal of Modern Physics E 17, no. 05 (May 2008): 771–801. http://dx.doi.org/10.1142/s0218301308010167.

Повний текст джерела

Анотація:

The status of the physics of heavy ion collisions is reviewed based on measurements over the past 6 years from the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The dense nuclear matter produced in Au + Au collisions with nucleon-nucleon c.m. energy [Formula: see text] at RHIC corresponds roughly to the density and temperature of the universe a few microseconds after the ‘big-bang’ and has been described as “a perfect liquid” of quarks and gluons, rather than the gas of free quarks and gluons, “the quark-gluon plasma” as originally envisaged. The measurements and arguments leading to this description will be presented.

Стилі APA, Harvard, Vancouver, ISO та ін.

28

NAKAGAWA, Y., A. NAKAMURA, T. SAITO, and H. TOKI. "CONFINING TIME-LIKE GLUON AND CONFINED SPATIAL GLUONS IN COULOMB GAUGE QCD." Modern Physics Letters A 23, no. 27n30 (September 30, 2008): 2352–55. http://dx.doi.org/10.1142/s0217732308029368.

Повний текст джерела

Анотація:

We investigate the Gribov-Zwanziger scenario in Coulomb gauge QCD using a SU(3) quenched lattice gauge simulation. The ghost propagator diverges in the infrared limit stronger than the free ghost propagator, and the ghost degree of freedom plays a central role in the confinement mechanism in the Coulomb gauge. The infrared divergent ghost dressing function results in the confining color-Coulomb instantaneous interaction. The equal-time transverse gluon propagator is suppressed in the infrared region. Therefore, in the Coulomb gauge, the instantaneous interaction mediated by time-like gluons is responsible for the confining force, and the would-be physical gluons are confined in hadrons.

Стилі APA, Harvard, Vancouver, ISO та ін.

29

SESHAVATHARAM, U. V. S., and S. LAKSHMINARAYANA. "SUPER SYMMETRY IN STRONG AND WEAK INTERACTIONS." International Journal of Modern Physics E 19, no. 02 (February 2010): 263–80. http://dx.doi.org/10.1142/s021830131001473x.

Повний текст джерела

Анотація:

For strong interaction two new fermion mass units 105.32 MeV and 11450 MeV are assumed. Existence of "Integral charge quark bosons", "Integral charge effective quark fermions", "Integral charge (effective) quark fermi-gluons" and "Integral charge quark boso-gluons" are assumed and their masses are estimated. It is noticed that, characteristic nuclear charged fermion is Xs · 105.32 = 938.8 MeV and corresponding charged boson is Xs(105.32/x) = 415.0 where Xs = 8.914 is the inverse of the strong coupling constant and x = 2.26234 is a new number by using which "super symmetry" can be seen in "strong and weak" interactions. 11450 MeV fermion and its boson of mass = 11450/x = 5060 MeV plays a crucial role in "sub quark physics" and "weak interaction". 938.8 MeV strong fermion seems to be the proton. 415 MeV strong boson seems to be the mother of the presently believed 493,496 and 547 MeV etc, strange mesons. With 11450 MeV fermion "effective quark-fermi-gluons" and with 5060 MeV boson "quark boso-gluon masses" are estimated. "Effective quark fermi-gluons" plays a crucial role in ground state charged baryons mass generation. Light quark bosons couple with these charged baryons to form doublets and triplets. "Quark boso-gluons" plays a crucial role in ground state neutral and charged mesons mass generation. Fine and super-fine rotational levels can be given by [I or (I/2)] power(1/4) and [I or (I/2)] power(1/12) respectively. Here, I = n(n+1) and n = 1, 2, 3, ….

Стилі APA, Harvard, Vancouver, ISO та ін.

30

Cohen-Tannoudji, Gilles, and Jean-Pierre Gazeau. "Cold Dark Matter: A Gluonic Bose–Einstein Condensate in Anti-de Sitter Space Time." Universe 7, no. 11 (October 25, 2021): 402. http://dx.doi.org/10.3390/universe7110402.

Повний текст джерела

Анотація:

In the same way as the realization of some of the famous gedanken experiments imagined by the founding fathers of quantum mechanics has recently led to the current renewal of the interpretation of quantum physics, it seems that the most recent progress of observational astrophysics can be interpreted as the realization of some cosmological gedanken experiments such as the removal from the universe of the whole visible matter or the cosmic time travel leading to a new cosmological standard model. This standard model involves two dark components of the universe, dark energy and dark matter. Whereas dark energy is usually associated with the cosmological constant, we propose explaining dark matter as a pure QCD effect, namely a gluonic Bose–Einstein condensate, following the transition from the quark gluon plasma phase to the colorless hadronic phase. Our approach not only allows us to assume a Dark/Visible ratio equal to 11/2 but also provides gluons (and di-gluons, viewed as quasi-particles) with an extra mass of vibrational nature. Such an interpretation would support the idea that, apart from the violation of the matter/antimatter symmetry satisfying the Sakharov’s conditions, the reconciliation of particle physics and cosmology needs not the recourse to any ad hoc fields, particles or hidden variables.

Стилі APA, Harvard, Vancouver, ISO та ін.

31

Kitazawa, Noriaki, and Yuki Sakai. "Constraints on gauge-Higgs unification models at the LHC." Modern Physics Letters A 31, no. 07 (March 2, 2016): 1650041. http://dx.doi.org/10.1142/s0217732316500413.

Повний текст джерела

Анотація:

We examine the possibility of observing the Kaluza–Klein (KK) gluons in gauge-Higgs unification models at the LHC with the energy [Formula: see text][Formula: see text]=[Formula: see text]14 TeV. We consider a benchmark model with the gauge symmetry SU(3)[Formula: see text]SU(3)W in five-dimensional spacetime, where SU(3)C is the gauge symmetry of the strong interaction and SU(3)W is that for the electroweak interaction and a Higgs doublet field. It is natural in general to introduce SU(3)C gauge symmetry in five-dimensional spacetime as well as SU(3)W gauge symmetry in gauge-Higgs unification (GHU) models. Since the fifth dimension is compactified to [Formula: see text] orbifold, there are KK modes of gluons in low-energy effective theory in four-dimensional spacetime. We investigate the resonance contribution of the first KK gluon to dijet invariant mass distribution at the LHC, and provide signal-to-noise ratios in various cases of KK gluon masses and kinematical cuts. Although the results are given in a specific benchmark model, we discuss their application to general GHU models with KK gluons. GHU models can be verified or constrained through the physics of the strong interaction, though they are proposed to solve the naturalness problem in electroweak symmetry breaking.

Стилі APA, Harvard, Vancouver, ISO та ін.

32

Celiberto, Francesco Giovanni. "A Journey into the Proton Structure: Progresses and Challenges." Universe 8, no. 12 (December 15, 2022): 661. http://dx.doi.org/10.3390/universe8120661.

Повний текст джерела

Анотація:

Unraveling the inner dynamics of gluons and quarks inside nucleons is a primary target of studies at new-generation colliding machines. Finding an answer to fundamental problems of Quantum ChromoDynamics, such as the origin of nucleon mass and spin, strongly depends on our ability of reconstructing the 3D motion of partons inside the parent hadrons. We present progresses and challenges in the extraction of TMD parton densities, with particular attention to the ones describing polarization states of gluons, which still represent a largely unexplored field. Then, we highlight connections with corresponding parton densities in the high-energy limit, the so-called unintegrated gluon distributions or UGDs and, more in general, to recent developments in high-energy physics.

Стилі APA, Harvard, Vancouver, ISO та ін.

33

JI, XIANGDONG, and YONG ZHAO. "PHYSICS OF GLUON HELICITY." International Journal of Modern Physics: Conference Series 25 (January 2014): 1460028. http://dx.doi.org/10.1142/s2010194514600283.

Повний текст джерела

Анотація:

The total gluon helicity in a polarized proton is shown to be a matrix element of a gauge-invariant but nonlocal, frame-dependent gluon spin operator [Formula: see text] in the large momentum limit. The operator [Formula: see text] is fit for the calculation of the total gluon helicity in lattice QCD. This calculation also implies that parton physics can be studied through the large momentum limit of frame-dependent, equal-time correlation functions of quarks and gluons.

Стилі APA, Harvard, Vancouver, ISO та ін.

34

OHKUMA, KAZUMASA, TOSHIYUKI MORII, and SATOSHI OYAMA. "CHARMED HADRON PRODUCTION AT RHIC." International Journal of Modern Physics A 18, no. 08 (March 30, 2003): 1481–84. http://dx.doi.org/10.1142/s0217751x03014952.

Повний текст джерела

Анотація:

To extract information about polarized gluon distribution in the proton, charmed hadron, actually [Formula: see text], productions at RHIC experiment are studied. We found that the spin correlation asymmetry between the initial proton and the produced [Formula: see text] is enable us to distinguish parameterization models of polarized gluons.

Стилі APA, Harvard, Vancouver, ISO та ін.

35

YANG, XIN-HUA, CHUN WA WONG, and KEH-CHENG CHU. "DRESSED QUARKS AND PROTON’S SPIN." Modern Physics Letters A 06, no. 13 (April 30, 1991): 1155–61. http://dx.doi.org/10.1142/s0217732391001202.

Повний текст джерела

Анотація:

The effect on the proton spin of mixing gluon and sea quark configurations is studied in a perturbative treatment based on the MIT bag model. As little as 29% of the proton spin is found to remain as the intrinsic spin of quarks when they are “dressed” by gluons.

Стилі APA, Harvard, Vancouver, ISO та ін.

36

Ivanov, N. Ya, A. V. Efremov, and O. V. Teryaev. "How to measure the linear polarization of gluons in unpolarized proton using the heavy-quark pair production." EPJ Web of Conferences 204 (2019): 02006. http://dx.doi.org/10.1051/epjconf/201920402006.

Повний текст джерела

Анотація:

In recent papers [1, 2], two new ways have been proposed to probe the linear polarization of gluons in unpolarized proton: using the azimuthal asymmetries and Callan-Gross ratio in heavy-quark pair leptoproduction, lN → l′QQ̅X. In this talk, we discuss in details the sensitivity of the QCD predictions for the azimuthal cos φ and cos 2φ asymmetries to the contribution of linearly polarized gluons inside unpolarized proton, where the azimuth φ is the angle between the lepton scattering plane (l, l′) and the heavy quark production plane (N, Q). Our analysis shows that the azimuthal distributions under consideration vary from 0 to 1 depending on the value of the gluonic counterpart of the Boer- Mulders function, $h_{1}^{ \bot g}$. We conclude that the cos φ and cos 2φ asymmetries in heavy-quark pair production in DIS processes are predicted to be large in wide kinematic ranges and sensitive to the contribution of linearly polarized gluons.

Стилі APA, Harvard, Vancouver, ISO та ін.

37

Rana, J. M. S., H. C. Chandola, and B. S. Rajput. "The quark confinement in extended gauge theory." Canadian Journal of Physics 69, no. 12 (December 1, 1991): 1441–46. http://dx.doi.org/10.1139/p91-213.

Повний текст джерела

Анотація:

To investigate the possible physical implications of the topological structure of non-Abelian dyons in connection with the issue of quark confinement in quantum chromodynamics (QCD), extended gauge theory is formulated in SU(2) and SU(3) gauge groups from the corresponding restricted chromodynamics (RCD) by reactivating the suppressed dynamical degrees of freedom and constructing the gauge potential in terms of the binding gluons (the RCD piece) and the valence gluons (the reactivated piece). It is shown that in this extended QCD, the confinement mechanism of the corresponding RCD remains intact. The physical spectrum contains color-singlet generalized electric glueballs made of valence gluon pairs as well as the generalized magnetic glueballs as massive collective modes of the condensed vacuum.

Стилі APA, Harvard, Vancouver, ISO та ін.

38

Shaparau, V. A., and V. I. Kuvshinov. "Nonperturbative Squeezed and Entangled Collinear Gluon States." Nonlinear Phenomena in Complex Systems 23, no. 4 (December 4, 2020): 435–41. http://dx.doi.org/10.33581/1561-4085-2020-23-4-435-441.

Повний текст джерела

Анотація:

We consider for the first time nonperturbative gluon state evolution up to the second order of smallness in time. Investigating gluon fluctuations at the nonperturbative stage we have proved theoretically the possibility of the existence of both single- and two-mode gluon squeezed states. The emergence of such remarkable states becomes pоssible owing to threeand four-gluon self-interactions. The three-gluon self-interaction leads to the squeezing effect at the next time stage of nonperturbative evolution.We have shown that the nonperturbative evolution during a short time leads both to colour squeezing and entanglement of gluons.

Стилі APA, Harvard, Vancouver, ISO та ін.

39

Alam, Jan-E., Pradip Roy, Sourav Sarkar, Sibaji Raha, and Bikash Sinha. "Thermal Masses and Equilibrium Rates in the Quark Gluon Phase." International Journal of Modern Physics A 12, no. 28 (November 10, 1997): 5151–60. http://dx.doi.org/10.1142/s0217751x97002759.

Повний текст джерела

Анотація:

We apply the momentum integrated Boltzmann transport equation to study the time evolution of various quark flavors in the central region of ultrarelativistic heavy ion collisions. The effects of thermal masses for quarks and gluons are incorporated to take into account the in-medium properties of these ingredients of the putative quark gluon plasma. We find that even under very optimistic conditions, complete chemical equilibration in the quark gluon plasma appears unlikely.

Стилі APA, Harvard, Vancouver, ISO та ін.

40

SALEEV, V. A., and N. P. ZOTOV. "HEAVY QUARK PHOTOPRODUCTION IN THE SEMIHARD APPROACH AT HERA AND BEYOND." Modern Physics Letters A 11, no. 01 (January 10, 1996): 25–35. http://dx.doi.org/10.1142/s0217732396000059.

Повний текст джерела

Анотація:

Processes of heavy quark photoproduction at HERA energies and beyond are investigated using the semihard (k⊥ factorization) approach. Virtuality and longitudinal polarization of gluons in the photon-gluon subprocess as well as the saturation effects in the gluon distribution function at small x have been taken into account. The total cross-sections, rapidity and p⊥ distributions of the charm and beauty quark photoproduction have been calculated. The results are compared with ZEUS experimental data for charm photoproduction cross-section.

Стилі APA, Harvard, Vancouver, ISO та ін.

41

BARONE, V., M. GENOVESE, N. N. NIKOLAEV, E. PREDAZZI, and B. G. ZAKHAROV. "BUILDING THE GLUON DISTRIBUTION IN NUCLEONS." International Journal of Modern Physics A 08, no. 16 (June 30, 1993): 2779–90. http://dx.doi.org/10.1142/s0217751x93001107.

Повний текст джерела

Анотація:

We present a direct perturbative QCD calculation of the gluon distribution in nucleons as a QCD radiative effect. We assume that the only infrared regulator is the nucleon's radius which emerges as a natural cutoff. A technique is introduced which allows constructing the glue step by step keeping a careful balance of valence, gluons and sea and obeying all constraints. The absolute normalization and shape of the calculated gluon distribution are in good agreement with the experimental determinations.

Стилі APA, Harvard, Vancouver, ISO та ін.

42

Noonan, H. W. "The Possibility of Unity." Philosophical Quarterly 70, no. 279 (July 22, 2019): 407–9. http://dx.doi.org/10.1093/pq/pqz038.

Повний текст джерела

Анотація:

Abstract In One Priest argues for the contradictoriness of Unity. The argument is that the unity of complex things is contradictory. It is contradictory that there are complex wholes composed of many parts. But there are. Thus, the explanation of unity has to be a contradictory entity, a gluon, which both is and is not an object. The book then develops and utilises a theory of gluons. The argument for the contradictoriness of Unity is crucial; without it there is no motivation for the theory of gluons. It fails. It does so because ‘because’ is a sentential connective. So what follows it must be a sentence, not a list. So Priest is wrong to say that in a complex whole there must be something, an entity, which binds the parts together.

Стилі APA, Harvard, Vancouver, ISO та ін.

43

Polonyi, J., and Z. Schram. "Compressing gluons." Nuclear Physics B - Proceedings Supplements 42, no. 1-3 (April 1995): 544–46. http://dx.doi.org/10.1016/0920-5632(95)00307-u.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

44

Machahari, Luxmi, and D. K. Choudhury. "Q2 dependence of the fractional momenta carried by small x quarks and gluons in models of proton structure function." Modern Physics Letters A 34, no. 33 (October 28, 2019): 1950273. http://dx.doi.org/10.1142/s0217732319502730.

Повний текст джерела

Анотація:

Recently, we suggested two alternative analytical models of proton structure function [Formula: see text] and gluon distribution [Formula: see text] at small [Formula: see text] [L. Machahari and D. K. Choudhury, Eur. Phys. J. A 54, 69 (2018); Commun. Theor. Phys. 71, 56 (2019)] derived from the coupled DGLAP equations for quarks and gluons approximated by Taylor expansion. In this work, we compute the partial momentum fractions carried by quarks and gluons in limited small [Formula: see text] range: [Formula: see text] and compare them with few other models available in the current literature. The analysis leads to understand qualitatively the effects of notions like Froissart saturation and self-similarity in the proton at small [Formula: see text]. We also study if our results conform to the total momentum fractions as predicted in perturbative and lattice QCD.

Стилі APA, Harvard, Vancouver, ISO та ін.

45

Fadin, V. S. "Three-Reggeon cuts in QCD amplitudes." EPJ Web of Conferences 222 (2019): 03006. http://dx.doi.org/10.1051/epjconf/201922203006.

Повний текст джерела

Анотація:

One of remarkable properties of QCD is the gluon Reggeization. The Reggeized gluon is the primary Reggeon in QCD; Pomeron and Odderon appear as compound states of the Reggeized gluons. Due to negative signature the Reggeized gluon gives the main contributions to high energy QCD amplitudes in each order ofperturbation theory. In the leading and next-to-leading logarithmic approximations these amplitudes aregiven by the Regge pole contributions. In the next-to-next-to-leading approximation the pole form of the amplitudes is violated by contributions of three-Reggeon cuts. We discuss these contributions to elastic QCD amplitudes.

Стилі APA, Harvard, Vancouver, ISO та ін.

46

Dunin, V., A. Gribowsky, E. Kokoulina, A. Kutov, V. Nikitin, V. Riadovikov, R. Shulyakovsky, V. Volkov, and A. Vorobiev. "Collective phenomena in hadron and nuclear interactions at high multiplicity." EPJ Web of Conferences 206 (2019): 03001. http://dx.doi.org/10.1051/epjconf/201920603001.

Повний текст джерела

Анотація:

Multiparticle production is described in the language of quarks and gluons. In the experiment the real hadrons are registered. For transfer from quarks and gluons to observed hadrons, various phenomenological models are used. In order to describe the high multiplicity region, we have developed a gluon dominance model. It represents a convolution of two stages. First stage is described by QCD. For second one (hadronisation), the phenomenological model is used. The description of topological cross sections in p $ \bar p $ collisions within of our model testifies that in hadron collisions the mechanism of hadronisation is being replaced by the recombination one. At that point, gluons play an active role in the multiparticle production process, and valence quarks are passive. They stay in the leading particles, and only the gluon splitting is responsible for the region of high multiplicity. The model with inclusion of intermediate quark charged topologies describes topological cross sections in annihilation. We observe the significant growth of a scaled variance of number of neutral pions with increasing of the total multiplicity at U-70 accelerator at IHEP (Protvino). The following experiment with 3.5 A GeV deuteron, lithium and carbon beams of the Nuclotron (JINR, Dubna) falling at a carbon target is carried out at the NIS-GIBS setup. The noticeable excess yield of soft photons(pT < 50 MeV/c) is observed. The existing models based on Monte Carlo simulation and theoretical estimations predict a lower yield. Our Collaboration plans to study excess of soft photon yield and other phenomena at the SPD (Spin Physics Detector) setup at JINR, Dubna with polarised beams of proton and light nuclei up to 25 GeV.

Стилі APA, Harvard, Vancouver, ISO та ін.

47

Musakhanov, M. M., and N. R. Rakhimov. "Heavy quarkonium potential at nonzero temperature in the instanton liquid model." International Journal of Modern Physics: Conference Series 49 (January 2019): 1960003. http://dx.doi.org/10.1142/s2010194519600036.

Повний текст джерела

Анотація:

Within the framework of the instanton Liquid Model (ILM) we evaluate the heavy quark [Formula: see text] potential at finite temperature. The potential in the ILM has two components: direct instantons contribution and the ILM modified one-gluon exchange contribution. The dynamical ”electric” mass [Formula: see text], which was generated by rescattering of the gluons from the ILM instantons, was taken into account.

Стилі APA, Harvard, Vancouver, ISO та ін.

48

Dimitrijević-Ćirić, Marija, Dragoljub Gočanin, Nikola Konjik, and Voja Radovanović. "Yang–Mills theory in the SO(2,3)⋆ model of noncommutative gravity." International Journal of Modern Physics A 33, no. 34 (December 10, 2018): 1845005. http://dx.doi.org/10.1142/s0217751x18450057.

Повний текст джерела

Анотація:

According to the standard cosmological model, thermodynamic conditions of the early Universe were such that nuclear matter existed in the state of quark–gluon plasma, rather than hadrons. On the other hand, it is generally believed that quantum gravity effects become ever more stronger as we approach the Big Bang, in particular, we expect that the phenomenon of space–time noncommutativity will be significant. Thus we are led to consider the properties of quarks and gluons in noncommutative space–time. For this, we employ the [Formula: see text] model of noncommutative gravity. As a first step towards the full theoretical treatment of the effects of noncommutativity on quark–gluon plasma, our main goal in this paper is to consistently incorporate Yang–Mills gauge fields in the [Formula: see text] framework and investigate their coupling to gravity that arises due to space–time noncommutativity. We construct an action that is invariant under deformed [Formula: see text] gauge transformations and expand it perturbatively in orders of the canonical deformation parameter [Formula: see text] via Seiberg–Witten map. In particular, we analyze the flat-space–time limit and demonstrate that residual noncommutativity induces various new couplings of quarks and gluons.

Стилі APA, Harvard, Vancouver, ISO та ін.

49

Scheuber, Hermann Josef. "Proton and Neutron as 3D Construction." European Journal of Applied Physics 4, no. 5 (September 20, 2022): 4–9. http://dx.doi.org/10.24018/ejphysics.2022.4.5.194.

Повний текст джерела

Анотація:

In this paper, there will be shown in construction how the virtual particles, the 3 quarks, build up with 3 gluons the Neutron and the Proton, the basic particles (together with the electrons) of the atoms. It is known that the whole matter consists of the 3 in confinement closed quark particles, for the Neutron as Down, down & up and for the Proton as Up, up & down, enhanced and reinforced with 3 gluon particles. The exact position of the 6 quarks and 8 gluons Elementary particles can be shown only constructively, as the constructions of Gell-Mann and Weinberg were removed in 1960 and 1967 by Quantum Mechanics and replaced by the laborious Lagrange mathematic formulas, therefore accessible only to a few experts. But here the non-mathematicians can see in a System of maximal probability the stationary order of Elementary particles.

Стилі APA, Harvard, Vancouver, ISO та ін.

50

TERAZAWA, HIDEZUMI. "A UNIFIED COMPOSITE MODEL OF QUARK–LEPTON COLOR INTERACTIONS." Modern Physics Letters A 13, no. 30 (September 28, 1998): 2427–31. http://dx.doi.org/10.1142/s0217732398002588.

Повний текст джерела

Анотація:

A unified composite model of quark–lepton SU(4) c color interactions in which 15 gauge bosons including a color-octet of gluons, a color-triplet of leptoquarks and their antiparticles, and a "B–L gluon" are made of a subquark and an antisubquark carrying the quark–lepton color quantum number is proposed. The SU(4) c symmetry is spontaneously broken down to SU(3) c due to the condensation of subquark–antisubquark pairs and the B–L gluon becomes [Formula: see text] times heavier than the leptoquarks.

Стилі APA, Harvard, Vancouver, ISO та ін.

Ми пропонуємо знижки на всі преміум-плани для авторів, чиї праці увійшли до тематичних добірок літератури. Зв'яжіться з нами, щоб отримати унікальний промокод!