Nonperturbative aspects of the QCD analytic invariant charge

In the framework of the analytic approach to Quantum Chromodynamics a new model for the strong running coupling has recently been developed. Its underlying idea is to impose the analyticity requirement on the perturbative expansion of the renormalization group $\beta$ function for restoring the correct analytic properties of the latter. The proposed model possesses a number of appealing features. Namely, the analytic invariant charge has no unphysical singularities at any loop level; it contains no free parameters; it has universal behavior both in ultraviolet and infrared regions at any loop level; and it possesses a fair higher loop and scheme stability. The extension of this model to the timelike region revealed the asymmetrical behavior of the running coupling in the intermediate- and low-energy domains of spacelike and timelike regions, that is essential when one handles the experimental data. The developed approach enables one to describe, in a consistent way, various strong interaction processes both of perturbative and intrinsically nonperturbative nature.Comment: Talk given at Tenth International QCD Conference (QCD 03), 2 - 9 July 2003, Montpellier, France; LaTeX2e, 4 pages, 4 EPS figure

The QCD analytic running coupling and chiral symmetry breaking

We study the dependence on the pion mass of the QCD effective charge by employing the dispersion relations for the Adler D function. This new massive analytic running coupling is compared to the effective coupling saturated by the dynamically generated gluon mass. A qualitative picture of the possible impact of the former coupling on the chiral symmetry breaking is presented

New analytic running coupling in spacelike and timelike regions

The new model for the QCD analytic running coupling, proposed recently, is extended to the timelike region. This running coupling naturally arises under unification of the analytic approach to QCD and the renormalization group (RG) formalism. A new method for determining the coefficients of the "analytized" RG equation is elaborated. It enables one to take into account the higher loop contributions to the new analytic running coupling (NARC) in a consistent way. The expression for the new analytic running coupling, independent of the normalization point, is obtained by invoking the asymptotic freedom condition. It is shown that the difference between the values of the NARC in respective spacelike and timelike regions is rather valuable for intermediate energies. This is essential for the correct extracting of the running coupling from experimental data. The new analytic running coupling is applied to the description of the inclusive $\tau$ lepton decay. The consistent estimation of the parameter $\Lambda_{QCD}$ is obtained here.Comment: REVTeX 3.1, 12 pages with 3 EPS figures; enlarged version is published in Phys. Rev.

QCDMAPT: program package for Analytic approach to QCD

A program package, which facilitates computations in the framework of Analytic approach to QCD, is developed and described in details. The package includes the explicit expressions for relevant spectral functions calculated up to the four-loop level and the subroutines for necessary integrals.Comment: 18 pages, 4 figures; QCDMAPT package is available from http://cpc.cs.qub.ac.uk/summaries/AEGP_v1_0.htm

Quark gap equation within the analytic approach to QCD

The compatibility between the QCD analytic invariant charge and chiral symmetry breaking is examined in detail. The coupling in question incorporates asymptotic freedom and infrared enhancement into a single expression, and contains only one adjustable parameter with dimension of mass. When inserted into the standard form of the quark gap-equation it gives rise to solutions displaying singular confining behavior at the origin. By relating these solutions to the pion decay constant, a rough estimate of about 880 MeV is obtained for the aforementioned mass-scale.Comment: Talk given by J.P. at 12th International QCD Conference (QCD05), 4 - 9 July 2005, Montpellier, France; 4 pages, 3 figure

Impact of the pion mass on nonpower expansion for QCD observables

A new set of functions, which form a basis of the massive nonpower expansion for physical observables, is presented in the framework of the analytic approach to QCD at the four-loop level. The effects due to the π meson mass are taken into account by employing the dispersion relation for the Adler function. The nonvanishing pion mass substantially modifies the functional expansion at low energies. Specifically, the spacelike functions are affected by the mass of the π meson in the infrared domain below few GeV, whereas the timelike functions acquire characteristic plateaulike behavior below the two-pion threshold. At the same time, all the appealing features of the massless nonpower expansion persist in the considered case of the nonvanishing pion mass

Quark-Hadron Duality and γ∗p→Δ\gamma^* p \to \Delta Form Factors

We use local quark-hadron duality to estimate the purely nonperturbative soft contribution to the $\gamma^*p\to \Delta$ form factors. Our results are in agreement with existing experimental data. We predict that the ratio $G_E^*(Q^2)/G_M^*(Q^2)$ is small for all accessible $Q^2$, in contrast to the pQCD expectations that $G_E^*(Q^2)\to -G_M^*(Q^2)$.Comment: 15 pages, LaTeX + 4 PS-figures enclosed in one uuencoded, compressed fil

Effect of the focusing magnetostatic field profile on the diffraction radiation oscillator excitation

Effect of the focusing magnetostatic field (FMF) profile on the output characteristics of diffraction radiation oscillator (DRO) is studied experimentally. The laboratory prototype of the mm range DRO produced in IRE NAS of Ukraine was used in the research. Peculiarities of the output power, oscillation frequency, starting current and other DRO characteristics for the cases of the decreasing, sagging and increasing magnetostatic field along the direction of the electron flow motion were determined. Prospects for the use of the increasing FMF in DRO are shown. При цитуванні документа, використовуйте посилання http://essuir.sumdu.edu.ua/handle/123456789/9323Експериментально досліджується вплив профілю фокусуючого магнітостатичного поля (ФМП) на вихідні характеристики генератора дифракційного випромінювання (ГДВ). Для дослідження використову-ється лабораторний зразок приладу – ГДВ мм діапазону, створеного в ІРЕ НАН України. Встановлені особливості зміни вихідної потужності, частоти генерації, стартового струму та інших характеристик генератора у випадку спадаючого, провисаючого або зростаючого магнітостатичного поля у напрямку руху електронного потоку. Відмічається перспектива застосування у ГДВ зростаючого ФМП. При цитировании документа, используйте ссылку http://essuir.sumdu.edu.ua/handle/123456789/9323Экспериментально исследуется влияние профиля фокусирующего магнито-статического поля (ФМП) на выходные характеристики генератора дифракционного излучения (ГДИ). При исследованиях используется лабораторный образец прибора – ГДИ мм диапазона, созданного в ИРЭ НАН Украины. Установлены особенности изменения выходной мощности, частоты генерации, пускового тока и других характеристик генератора в случаях спадающего, провисающего или нарастающего магнитостатического поля в направлении движения электронного потока. Показана перспектива использования в ГДИ нарастающего ФМП. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/932

On the low-energy behavior of the Adler function

The infrared behavior of the Adler function is examined by making use of a recently derived integral representation for the latter. The obtained result for the Adler function agrees with its experimental prediction in the entire energy range. The inclusive $\tau$ lepton decay is studied in the framework of the developed approach.Comment: Talk given at 14th International QCD Conference (QCD 08), 7 - 12 July 2008, Montpellier, France; 4 pages, 1 figur

Strategic Priorities in Development of the Agro-Industrial Complex of the Krasnodar Region

The paper gives the agro-industrial complex characteristic of the Krasnodar Krai, analyzes the condition of its branches and defines key problems. It emphasizes such strategic development priorities of the agro-industrial complex of the Krasnodar Krai as the reclamation of land, development of the elite seed industry, intensive development of the animal industry, support of the small forms of economic management. The paper also considers the possibilities of the state support for regional agroproducers taking into account the entry of the Russian Federation in the ranks of the World Trade Organization. In compliance with that the paper offers the measures of the state regulation that is aimed to stimulation of key directions of the agrarian industry development of the region where the matter concerns a creation of the logistic basis and formation of the rural cooperation. As an example a model of the contract relations system concerning production, processing and sales of the pig-breeding products between the agricultural organizations, farm enterprises and farms of the population which can be used during the organization of productive processes both in other subsectors of the animal industry and in the branch of the plant industry. There is a conclusion that now a concentration of the state regulation on the oblique support measures for strategic development directions that is capable to provide a stimulation of "independent mechanisms" of the inner potential of the agro-industrial complex of the Krasnodar Krai. DOI: 10.5901/mjss.2015.v6n5s3p17