Simple parameterization of nuclear attenuation data

Based on the nuclear attenuation data obtained by the HERMES experiment on nitrogen and krypton nuclei, it is shown that the nuclear attenuation $R_M^{h}$ can be parametrised in a form of a linear polynomial $P_1=a_{11}$ + $\tau a_{12}$, where $\tau$ is the formation time, which depends on the energy of the virtual photon $\nu$ and fraction of that energy $z$ carried by the final hadron. Three widely known parameterizations for $\tau$ were used for the performed fit. The fit parameters $a_{11}$ and $a_{12}$ do not depend on $\nu$ and $z$

Possible influence of the two string events on the hadron formation in a nuclear environment

One of the basic assumptions of the string model is that as a result of a DIS in nucleus a single string arises, which then breaks into hadrons. However the pomeron exchange considered in this work, leads to the production of two strings in the one event. The hadrons produced in these events have smaller formation lengths, than those with the same energy produced in the single string events. As a consequence, they undergo more substantial absorption in the nuclear matter

Q(2) dependence of nuclear transparency for exclusive rho(0) production

Exclusive coherent and incoherent electroproduction of the rho(0) meson from H-1 and N-14 targets has been studied at the HERMES experiment as a function of coherence length (l(c)), corresponding to the lifetime of hadronic fluctuations of the virtual photon, and squared four-momentum of the virtual photon (-Q(2)). The ratio of N-14 to H-1 cross sections per nucleon, called nuclear transparency, was found to increase (decrease) with increasing l(c) for coherent (incoherent) rho(0) electroproduction. For fixed l(c), a rise of nuclear transparency with Q(2) is observed for both coherent and incoherent rho(0) production, which is in agreement with theoretical calculations of color transparency

Nuclear Attenuation of high energy two-hadron system in the string model

Nuclear attenuation of the two-hadron system is considered in the string model. The two-scale model and its improved version with two different choices of constituent formation time and sets of parameters obtained earlier for the single hadron attenuation, are used to describe available experimental data for the $z$-dependence of subleading hadron, whereas satisfactory agreement with the experimental data has been observed. A model prediction for $\nu$-dependence of the nuclear attenuation of the two-hadron system is also presented.Comment: 8 page

Evidence for quark-hadron duality in the proton spin asymmetry A(1)

Spin-dependent lepton-nucleon scattering data have been used to investigate the validity of the concept of quark-hadron duality for the spin asymmetry A(1). Longitudinally polarized positrons were scattered off a longitudinally polarized hydrogen target for values of Q(2) between 1.2 and 12 GeV2 and values of W-2 between 1 and 4 GeV2. The average double-spin asymmetry in the nucleon resonance region is found to agree with that measured in deep-inelastic scattering at the same values of the Bjorken scaling variable x. This finding implies that the description of A(1) in terms of quark degrees of freedom is valid also in the nucleon resonance region for values of Q(2) above 1.6 GeV2

Плевральный выпот при раке легкого

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ПРОЕКТ ФЕДЕРАЛЬНЫЕ ТЕРРИТОРИИ КАК ОБЪЕКТ ПРОСТРАНСТВЕННОГО РАЗВИТИЯ СИБИРИ И ДАЛЬНЕГО ВОСТОКА РОССИИ

The study is devoted to the spatial development of Siberia and the Far East of Russia. The role of federal districts as established macro-regions is considered - in optimizing territorial planning and correction of subjects of interregional management, and isolating project federal territories on their basis - as objects of sustainable-safe spatial development. The main focus is on the formation of a promising spatial (infrastructure) framework for the development of macroregions, including the identification of advanced growth nodes (the so-called “second” and “third” cities of macroregional subjects) and the links between them (transport axes and corridors) that are significant in the global economic context. The findings of the study can be used both in strategic planning at the level of federal districts and in further research at the national and interregional levels.El estudio está dedicado al desarrollo espacial de Siberia y el Lejano Oriente de Rusia. El papel de los distritos federales como macrorregiones establecidas se considera, en la optimización de la planificación territorial y la corrección de los temas de la gestión interregional, y el aislamiento de los territorios federales del proyecto, como objetos de desarrollo espacial sostenible y seguro. El enfoque principal es la formación de un marco espacial (infraestructura) prometedor para el desarrollo de macrorregiones, incluida la identificación de nodos de crecimiento avanzados (las llamadas "segunda" y "tercera" ciudades de sujetos macrorregionales) y los vínculos entre ellas (ejes y corredores de transporte) que son significativos en el contexto económico global. Los hallazgos del estudio pueden utilizarse tanto en la planificación estratégica a nivel de distritos federales como en investigaciones adicionales a nivel nacional e interregional.Исследование посвящено пространственному развитию Сибири и Дальнего Востока России. Рассмотрена роль федеральных округов как установленных макрорегионов-в оптимизации территориального планирования и коррекции субъектов межрегионального управления, а также изоляции на их основе проектных федеральных территорий - как объектов устойчивого-безопасного пространственного развития. Основное внимание уделяется формированию перспективной пространственной (инфраструктурной) основы развития макрорегионов, в том числе выявлению опережающих узлов роста (так называемых “вторых” и “третьих” городов макрорегионов) и связей между ними (транспортных осей и коридоров), значимых в глобальном экономическом контексте. Результаты исследования могут быть использованы как в области стратегического планирования на уровне федеральных округов и в дальнейших исследованиях на национальном и межрегиональном уровнях