Russia and the Arab Spring: supporting the counter-revolution

Russia’s response to the Arab Spring ranged from apprehension to deep anxiety and diverged significantly from the US and the EU responses. While initially welcoming the popular demands for political reform in North Africa, the Russian reaction rapidly became more critical as a result of Western military intervention into Libya and the threat of the spread of Islamist extremism. It was these twin fears which prompted the Russian leadership to adopt an uncompromizing stance towards Syria. While geopolitical factors certainly played a role in driving Russian strategy, domestic political factors were also more significant. As the Russian leadership felt internally threatened by the growing opposition within the country, conflict in the Middle East highlighted the perceived flaws of the imposition of Western liberal democracy and the virtues of Russia’s own model of state-managed political order. There was, as such, a significant ideational and ideological dimension to the Russian response to the Arab Spring

Leading-Order Actions of Goldstino Fields

This paper starts with a self-contained discussion of the so-called Akulov-Volkov action S_AV, which is traditionally taken to be the leading-order action of Goldstino field. Explicit expressions for S_AV and its chiral version S_AV^ch are presented. We then turn to the issue on how these actions are related to the leading-order action S_NL proposed in the newly proposed constrained superfield formalism. We show that S_NL may yield S_AV/S_AV^ch or a totally different action S_KS, depending on how the auxiliary field in the former is integrated out. However, S_KS and S_AV/S_AV^ch always yield the same S-matrix elements, as one would have expected from general considerations in quantum field theory.Comment: Minor changes, version to appear in European Physical Journal

Relation between flux formation and pairing in doped antiferromagnets

We demonstrate that patterns formed by the current-current correlation function are landmarks which indicate that spin bipolarons form in doped antiferromagnets. Holes which constitute a spin bipolaron reside at opposite ends of a line (string) formed by the defects in the antiferromagnetic spin background. The string is relatively highly mobile, because the motion of a hole at its end does not raise extensively the number of defects, provided that the hole at the other end of the line follows along the same track. Appropriate coherent combinations of string states realize some irreducible representations of the point group C_4v. Creep of strings favors d- and p-wave states. Some more subtle processes decide the symmetry of pairing. The pattern of the current correlation function, that defines the structure of flux, emerges from motion of holes at string ends and coherence factors with which string states appear in the wave function of the bound state. Condensation of bipolarons and phase coherence between them puts to infinity the correlation length of the current correlation function and establishes the flux in the system.Comment: 5 pages, 6 figure

Plasma-surface interaction during iter transient events: simulation with QSPA Kh-50 AND GOL-3 facilities

The paper presents experimental investigations of plasma-surface interaction (PSI) and materials behavior under plasma loads relevant to giant ELMs in ITER. The experiments were performed with QSPA Kh-50 and GOL-3 devices located in Kharkov, (Ukraine) and Novosibirsk (Russia) respectively. QSPA provided repetitive plasma pulses of the duration of 0.25 ms and the energy density up to 2.5 MJ/m². In GOL-3 multimirror trap the impacting plasma was heated up to 2…4 keV temperature by a high power relativistic electron beam (0.8 MeV, ~30 kA, ~12 µs, ~120 kJ). Surface morphology of the targets exposed to QSPA and GOL-3 plasma is analyzed. Development of cracking on the tungsten surface and droplets splashing are discussed.Представлені результати досліджень взаємодії плазми з поверхнею й поведінки матеріалів при плазмових навантаженнях, відповідних граничним локалізованим модам в ІТЕРі. Експерименти проводились на установках КСПП Х-50 (Харків) й ГОЛ-3 (Новосибірськ). Опромінення на КСПП проводилось повторюваними імпульсами тривалістю 0,25 мс та густиною енергії до 2,5 МДж/м². У гофрованій багатопробочній пастці ГОЛ-3 плазма, яка взаємодіє з матеріалами, нагрівалась до температури 2…4 кеВ потужним релятивістським електронним пучком (0.8 MеВ, ~30 кA, ~12 мкс, ~120 кДж). Аналізується морфологія поверхні мішеней, що опромінені на КСПП та ГОЛ-3. Обговорюється розвиток тріщин й крапельна ерозія вольфраму.Представлены результаты исследований взаимодействия плазмы с поверхностью и поведения материалов при плазменных нагрузках, соответствующих граничным локализованным модам в ИТЭРе. Эксперименты проводились на установках КСПУ Х-50 (Харьков) и ГОЛ-3 (Новосибирск). Облучение на КСПУ проводилось повторяющимися импульсами длительностью 0,25 мс и плотностью энергии до 2,5 МДж/м². В гофрированной многопробочной ловушке ГОЛ-3 взаимодействующая с материалами плазма нагревалась до температуры 2…4 кэВ мощным релятивистским электронным пучком (0.8 MэВ, ~30 кA, ~12 мкс, ~120 кДж). Анализируется морфология поверхности мишеней, облученных на КСПУ и ГОЛ-3. Обсуждается развитие трещин и капельная эрозия вольфрама

New technological possibilities to prepare InP epitaxial layers, as well as ohmic and barrier contacts to them, and the properties of microwave diodes made on their basis

A novel technological approach to fabrication of n-InP autoepitaxial films LPE-grown on porous n⁺-InP substrates, as well as ohmic and barrier contacts to them using (quasi)amorphous TiBx interstitial phases, is proposed. We demonstrate the advantages of TiBx−n-n⁺-n⁺⁺-InP Schottky-barrier diodes made on porous substrates over those made on the standard rigid substrates, as well as the possibility to make Gunn diodes (intended for the 120−150 GHz frequency range) on the InP epitaxial structures grown on porous substrates

Porous nanostructured InP: technology, properties, application

We prepared porous InP (100) substrates with a nanostructured surface relief on which InP epitaxial films were grown. The structure, morphological, and photoluminescence properties of nanostructured substrates and InP epilayers grown on them were studied. These InP epilayers grown on the porous and standard InP substrates were used to make microwave diodes. We showed the advantages of the diodes made on the porous substrates (over those made on the standard ones) caused by higher structural perfection of the InP epilayers grown on the porous substrates

Detector Description and Performance for the First Coincidence Observations between LIGO and GEO

For 17 days in August and September 2002, the LIGO and GEO interferometer gravitational wave detectors were operated in coincidence to produce their first data for scientific analysis. Although the detectors were still far from their design sensitivity levels, the data can be used to place better upper limits on the flux of gravitational waves incident on the earth than previous direct measurements. This paper describes the instruments and the data in some detail, as a companion to analysis papers based on the first data.Comment: 41 pages, 9 figures 17 Sept 03: author list amended, minor editorial change

Anisotropic flow of charged hadrons, pions and (anti-)protons measured at high transverse momentum in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}}=2.76 TeV

The elliptic, $v_2$, triangular, $v_3$, and quadrangular, $v_4$, azimuthal anisotropic flow coefficients are measured for unidentified charged particles, pions and (anti-)protons in Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV with the ALICE detector at the Large Hadron Collider. Results obtained with the event plane and four-particle cumulant methods are reported for the pseudo-rapidity range $|\eta|<0.8$ at different collision centralities and as a function of transverse momentum, $p_{\rm T}$, out to $p_{\rm T}=20$ GeV/$c$. The observed non-zero elliptic and triangular flow depends only weakly on transverse momentum for $p_{\rm T}>8$ GeV/$c$. The small $p_{\rm T}$ dependence of the difference between elliptic flow results obtained from the event plane and four-particle cumulant methods suggests a common origin of flow fluctuations up to $p_{\rm T}=8$ GeV/$c$. The magnitude of the (anti-)proton elliptic and triangular flow is larger than that of pions out to at least $p_{\rm T}=8$ GeV/$c$ indicating that the particle type dependence persists out to high $p_{\rm T}$.Comment: 16 pages, 5 captioned figures, authors from page 11, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/186

Centrality dependence of charged particle production at large transverse momentum in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm{NN}}} = 2.76 TeV

The inclusive transverse momentum ($p_{\rm T}$) distributions of primary charged particles are measured in the pseudo-rapidity range $|\eta|<0.8$ as a function of event centrality in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}=2.76$ TeV with ALICE at the LHC. The data are presented in the $p_{\rm T}$ range $0.15<p_{\rm T}<50$ GeV/$c$ for nine centrality intervals from 70-80% to 0-5%. The Pb-Pb spectra are presented in terms of the nuclear modification factor $R_{\rm{AA}}$ using a pp reference spectrum measured at the same collision energy. We observe that the suppression of high-$p_{\rm T}$ particles strongly depends on event centrality. In central collisions (0-5%) the yield is most suppressed with $R_{\rm{AA}}\approx0.13$ at $p_{\rm T}=6$-7 GeV/$c$. Above $p_{\rm T}=7$ GeV/$c$, there is a significant rise in the nuclear modification factor, which reaches $R_{\rm{AA}} \approx0.4$ for $p_{\rm T}>30$ GeV/$c$. In peripheral collisions (70-80%), the suppression is weaker with $R_{\rm{AA}} \approx 0.7$ almost independently of $p_{\rm T}$. The measured nuclear modification factors are compared to other measurements and model calculations.Comment: 17 pages, 4 captioned figures, 2 tables, authors from page 12, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/284