Theory and phenomenology of helicity amplitudes for high energy exclusive leptoproduction of the rho-meson

We review here two approaches to describe hard leptoproduction of transversally polarized rho-meson, based on recent calculation of the gamma*T -> rhoT impact factor up to twist 3 accuracy in the collinear factorization frame, including 2- and 3- particles Fock-states. The first approach uses a model of the unintegrated gluon density (the proton impact factor) which allows a comparison of our predictions with H1 and ZEUS data for the ratios of helicity amplitudes T(gamma*T -> rhoT)/T(gamma*L -> rhoL) and T(gamma*T -> rhoL)/T(gamma*L -> rhoL). In the second approach, we transform the gamma*T -> rhoT impact factor into the impact parameter space. We show that the transformed amplitude factorizes according to conventional dipole picture. We shortly discuss a way to implement the nucleon saturation effects in our approach.Comment: 5 pages, 2 figures, to appear in the proceedings of 6th International Conference on Quarks and Nuclear Physics (QNP 2012), Palaiseau, France, April 16-20, 201

High Energy exclusive Leptoproduction of the rho-meson: Theory and Phenomenology

We describe the hard leptoproduction of transversally polarized rho-meson, up to twist 3 accuracy, including 2- and 3- particles Fock-states, in the HERA kinematics of high center-of-mass energy. We first build a model based on a simple approach to the unintegrated gluon density (the parton impact factor) that we compare with H1 and ZEUS data for the ratios of helicity amplitudes T(gamma*T -> rhoT)/T(gamma*L -> rhoL) and T(gamma*T -> rhoL)/T(gamma*L -> rhoL) and get a good description of the data. We also show how saturation effects can be included in this model by extending the dipole representation of the scattering amplitude in coordinate space up to twist 3.Comment: 4 pages, 3 figures, to appear in the proceedings of 20th International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS 2012), Bonn, Germany, 26-30 March 201

A phenomenological study of helicity amplitudes of high energy exclusive leptoproduction of the rho meson

We apply a previously developed scheme to consistently include the twist-3 distribution amplitudes for transversely polarized rho meson in order to evaluate, in the framework of kT factorization, the helicity amplitudes for exclusive leptoproduction of a light vector meson, at leading order in alphaS. We compare our results with high energy experimental data for the ratios of helicity amplitudes T11/T00 and T01/T00 and get a good description of the data.Comment: 20 pages, 11 figures, published version in PR

Model study of generalized parton distributions with helicity flip

Generalized parton distributions with helicity flip are studied in the quark sector, within a simple version of the MIT bag model, assuming an SU(6) wave function for the proton target. In the framework under scrutiny it turns out that only the generalized transversity distribution, H_T^q, is non vanishing. For this quantity, the forward limit is properly recovered and numerical results are found to underestimate recent lattice data for its first moment. Positivity bounds recently proposed are fulfilled by the obtained distribution. The relevance of the analysis for the planning of measurements of the quark generalized transversity is addressed.Comment: 15 pages, 4 figures; shortened version accepted for publication in Phys. Rev.

“We did not Send You There”: Media Representations of the War in Afghanistan and the Emergence and Practice of Cancel Culture in Post-Soviet Russia

The article is devoted to the problem of transformation of historical memory in the context of digitalization. The aim of the article is to make a critical analysis of the “cancel culture” as one of the tools for the formation and transmission of historical identity in digital space and beyond. The new media space from where the phenomenon of cancel culture originated is chosen as the research field. The objective of the article is then to bring the conceptual subjects of memory studies and media theory closer together. New media differ significantly from traditional media, and these differences determine the change in discursive rules and consequently imply a reorganization of the discursive space.  The vertical paternalistic structure of discourse gives way to a horizontal rhizomatic structure, while the rigid author-reader opposition breaks down. The change in discursive rules entails a change of discursive practices. The changes affect not only discursive but also social space, including the space of historical memory. The digitalization of the past entails new forms of memory existence. At the same time, some traditional functions, such as identity formation, are preserved. New media becomes a platform for identity formation, providing opportunities for the construction and constant reassembly of identities. The article considers “cancel culture” as a marker of this reassembly. It is viewed both as a mode of manifestation and as a source of identity. The critical analysis highlights both the negative and positive characteristics of the phenomenon, explaining its paradoxicality and regularity in the new reality

On high energy exclusive leptoproduction of the rho meson up to twist 3

The Regge inspired k_T-factorization scheme expresses the scattering amplitude for exclusive leptoproduction of a light vector meson rho in terms of two impact factors, one for the gamma* - rho transition and the other one for the nucleon to nucleon transition, with, at leading order, a two "reggeized" gluon exchange in the t-channel. We report here on a recent phenomenological study where we apply a previously developped scheme which consistently takes into account the twist 3 distribution amplitudes for transversely polarized rho meson. The computation of the gamma* to rho impact factor are performed within collinear factorization of QCD, up to the twist 3 level, based on the Collinear Factorization scheme applied to the amplitudes gamma*g to g rho . Our results are in good agreement with high energy experimental data for the ratios of helicity amplitudes.Comment: 3 pages, 4 figures, To be published in the proceedings of the 2011 Europhysics Conference on High Energy Physics-HEP 2011, July 21-27, 2011 Grenoble, Rhone-Alpes, Franc

Modeling of operating history of the research nuclear reactor

The results of simulation of the IRT-T reactor operation history from 2012 to 2014 are presented. Calculations are performed using continuous energy Monte Carlo code MCU-PTR. Comparison is made between calculation and experimental data for the critical reactor

Materials on the Lepidoptera fauna of the Dagestan Republic (Northeastern Caucasus, Russia): autumn aspect (Insecta: Lepidoptera)

The article provides the list of Lepidoptera (the families: Cossidae, Coleophoridae, Choreutidae, Ethmiidae, Pterophoridae, Pyralidae, Crambidae, Lemoniidae, Lasiocampidae, Drepanidae, Geometridae, Sphingidae, Erebidae, Noctuidae, Lycaenidae, Nymphalidae, Pieridae), collected in four localities in the Republic of Dagestan in September 2020. In total, 207 species have been recorded. Five species are reported for the fauna of Russia for the first time: Casignetella texanella (Chambers, 1878) (Coleophoridae), Agriphila cyrenaicellus (Ragonot, 1887), Thyridiphora furia (Swinhoe, 1884), Haritalodes derogata (Fabricius, 1775) (Crambidae), and Scopula minorata (Boisduval, 1833) (Geometridae); 23 species - for the fauna of Eastern Caucasus: Perygra glaucicolella (Wood, 1892), Ecebalia halophilella (Zimmermann, 1926), E. linosyris (E. Hering, 1937), Ionescumia clypeiferella (O. Hofmann, 1871), Carpochena trientella (Christpoh, 1872) (Coleophoridae), Tebenna micalis (Mann, 1857) (Choreutidae), Ethmia candidella (Alpheraky, 1908) (Ethmiidae), Stenoptilia zophodactyla (Duponchel, 1838), Stenoptilodes taprobanes (Felder & Rogenhofer, 1875), Crombrugghia laetus (Zeller, 1847) (Pterophoridae), Glyptoteles leucacrinella Zeller, 1848, Cadra calidella (Guenée, 1845), (Pyralidae), Agriphila selasella (Hübner, 1813), Agriphila tolli (Bleszynski, 1952), Agriphila poliellus (Treitschke, 1832), Pediasia contaminella (Hübner, 1796), Pediasia fascelinella (Hübner, [1813]), Uresiphita gilvata (Fabricius, 1794), Antigastra catalaunalis (Duponchel, 1833) (Crambidae), Watsonalla binaria (Hufnagel, 1767) (Drepanidae), Idaea degeneraria erschoffi (Christoph, 1872), Scopula nigropunctata (Hufnagel, 1767), and Rhodometra sacraria (Linnaeus, 1767) (Geometridae)

The quasiclassical theory of the Dirac equation with a scalar-vector interaction and its applications in the theory of heavy-light mesons

We construct a relativistic potential quark model of $D$, $D_s$, $B$, and $B_s$ mesons in which the light quark motion is described by the Dirac equation with a scalar-vector interaction and the heavy quark is considered a local source of the gluon field. The effective interquark interaction is described by a combination of the perturbative one-gluon exchange potential $V_{\mathrm{Coul}}(r)=-\xi/r$ and the long-range Lorentz-scalar and Lorentz-vector linear potentials $S_{\mathrm{l.r.}}(r)=(1-\lambda)(\sigma r+V_0)$ and $V_{\mathrm{l.r.}}(r)=\lambda(\sigma r+V_0)$, where $0\leqslant\lambda<1/2$. Within the quasiclassical approximation, we obtain simple asymptotic formulas for the energy and mass spectra and for the mean radii of $D$, $D_s$, $B$, and $B_s$ mesons, which ensure a high accuracy of calculations even for states with the radial quantum number $n_r\sim 1$. We show that the fine structure of P-wave states in heavy-light mesons is primarily sensitive to the choice of two parameters: the strong-coupling constant $\alpha_s$ and the coefficient $\lambda$ of mixing of the long-range scalar and vector potentials $S_{\mathrm{l.r.}}(r)$ and $V_{\mathrm{l.r.}}(r)$. The quasiclassical formulas for asymptotic coefficients of wave function at zero and infinity are obtained.Comment: 22 pages, 6 figure

Free-radical oxidation as a pathogenetic factor of metabolic syndrome

The medical and social significance of cardiovascular diseases remains high. One of the factors that determine cardiovascular risks is metabolic syndrome. As a result of excessive accumulation of lipid and carbohydrate metabolism products in metabolic syndrome, oxidative (oxidative) stress develops. The article considers both domestic and foreign scientific studies, which highlight various aspects of the influence of reactive oxygen and nitrogen species, as well as other free radicals on the formation of oxidative stress in pathological conditions that are part of the metabolic syndrome complex. This describes the mechanisms of the formation of chronic inflammation through excessive secretion of pro-inflammatory cytokines and adipokines, activation of the transcription factor NF-kB, as well as damage to the antioxidant system in obesity. Separately, a number of mechanisms of the stimulating effect of adipokines: leptin, adiponectin, chimerine, omentin 1, resistin, on the formation of oxidative stress have been noted. The ways of activating the polyol pathway, as well as diacyl-glycerol — protein kinase C — the signaling pathway of oxidative stress, the formation of mitochondrial dysfunction is described. As a result of which there is an excessive production of free radicals in insulin resistance, diabetes mellitus and macroand microvascular complications of diabetes. In addition, the influence of oxidative stress directly on the formation of cardiovascular diseases of atherosclerotic genesis, as well as arterial hypertension, has been shown