Soviet Leaders in Western Media Space

The results of the analysis of the USSR image in Western social media are presented. The novelty of the study lies in the use of the Global Database of Events, Language, and Tone in the analysis of the image of Soviet leaders in the Euro-Atlantic press. A review of messages that mention the names of the leaders of the USSR from January 1, 2017 to the present in the Western press has been completed. It is proved that the overall emotional tone of the narrative about the Soviet leaders in Western media is extremely negative. It is noted that French and German journalists, in comparison with Anglo-Saxon ones, more often write about Soviet history in a positive context. It is emphasized that the differences correlate with the quality of relations between Western countries and Russia, as well as the prospects for their improvement. It is shown that journalists, discussing the Soviet leaders, raise existential questions that are important for the Euro-Atlantic mass consciousness. The relevance of the study is due to the fact that the growth of media interest in the stories of rapprochement between the USSR and the West, as well as the emotionally positive transformation of the images of Soviet leaders in the media is considered as a condition and indicator of improving relations between Russia and the West

Ground state instability in systems of strongly interacting fermions

We analyze stability of a fermion system with model repulsive pair interaction potential. The possibility for different types of restructuring of the Fermi ground state (at sufficiently great coupling constant) is related to the analytic properties of such potential. In particular, for the screened Coulomb law it is shown that the restructuring cannot be of the Fermi condensation type, known earlier for some exactly solvable models, and instead it belongs to the class of topological transitions (TT). For this model, a phase diagram has been built in the variables "screening parameter - coupling constant" which displays two kinds of TT: a 5/2-kind similar to the known Lifshitz transitions in metals, and a 2-kind characteristic for a uniform strongly interacting system.Comment: The article has 11 pages, in Latex 2e (from Lyx), 3 eps figures or a ps fil

Anomalous asymmetry of magnetoresistance in NbSe3_3 single crystals

A pronounced asymmetry of magnetoresistance with respect to the magnetic field direction is observed for NbSe$_3$ crystals placed in a magnetic field perpendicular to their conducting planes. It is shown that the effect persists in a wide temperature range and manifests itself starting from a certain magnetic induction value $B_0$, which at $T=4.2$ K corresponds to the transition to the quantum limit, i.to the state where the Landay level splitting exceeds the temperature.Comment: 4 pages, 6 figures, to be appeared in JETP Let

Spontaneous breaking of four-fold rotational symmetry in two-dimensional electronic systems explained as a continuous topological transition

The Fermi liquid approach is applied to the problem of spontaneous violation of the four-fold rotational point-group symmetry ($C_4$) in strongly correlated two-dimensional electronic systems on a square lattice. The symmetry breaking is traced to the existence of a topological phase transition. This continuous transition is triggered when the Fermi line, driven by the quasiparticle interactions, reaches the van Hove saddle points, where the group velocity vanishes and the density of states becomes singular. An unconventional Fermi liquid emerges beyond the implicated quantum critical point.Comment: 6 pages, 4 figure

Second wind of the Dulong-Petit Law at a quantum critical point

Renewed interest in 3He physics has been stimulated by experimental observation of non-Fermi-liquid behavior of dense 3He films at low temperatures. Abnormal behavior of the specific heat C(T) of two-dimensional liquid 3He is demonstrated in the occurrence of a T-independent term in C(T). To uncover the origin of this phenomenon, we have considered the group velocity of transverse zero sound propagating in a strongly correlated Fermi liquid. For the first time, it is shown that if two-dimensional liquid 3He is located in the vicinity of the quantum critical point associated with a divergent quasiparticle effective mass, the group velocity depends strongly on temperature and vanishes as T is lowered toward zero. The predicted vigorous dependence of the group velocity can be detected in experimental measurements on liquid 3He films. We have demonstrated that the contribution to the specific heat coming from the boson part of the free energy due to the transverse zero-sound mode follows the Dulong-Petit Law. In the case of two-dimensional liquid 3He, the specific heat becomes independent of temperature at some characteristic temperature of a few mK.Comment: 5 pages, 1 figur

Quasiparticles in a strongly correlated liquid with the fermion condensate: applications to high-temperature superconductors

A model of a strongly correlated electron liquid based on the fermion condensation (FC) is extended to high-temperature superconductors. Within our model, the appearance of FC presents a boundary separating the region of a strongly interacting electron liquid from the region of a strongly correlated electron liquid. We study the superconductivity of a strongly correlated liquid and show that under certain conditions, the superconductivity vanishes at temperatures $T>T_c\simeq T_{node}$, with the superconducting gap being smoothly transformed into a pseudogap. As the result, the pseudogap occupies only a part of the Fermi surface. The gapped area shrinks with increasing the temperature and vanishes at $T=T^*$. The single-particle excitation width is also studied. The quasiparticle dispersion in systems with FC can be represented by two straight lines characterized by the respective effective masses $M^*_{FC}$ and $M^*_L$, and intersecting near the binding energy that is of the order of the superconducting gap. It is argued that this strong change of the quasiparticle dispersion at the binding can be enhanced in underdoped samples because of strengthening the FC influence. The FC phase transition in the presence of the superconductivity is examined, and it is shown that this phase transition can be considered as kinetic energy driven.Comment: 16 pages, 3 figures, minor grammatical changes, revised and accepted by JET

Measurement of the K+→μ+νμγK^+\rightarrow{\mu^+}{\nu_{\mu}}{\gamma} decay form factors in the OKA experiment

A precise measurement of the vector and axial-vector form factors difference $F_V-F_A$ in the $K^+\rightarrow{\mu^+}{\nu_{\mu}}{\gamma}$ decay is presented. About 95K events of $K^+\rightarrow{\mu^+}{\nu_{\mu}}{\gamma}$ are selected in the OKA experiment. The result is $F_V-F_A=0.134\pm0.021(stat)\pm0.027(syst)$. Both errors are smaller than in the previous $F_V-F_A$ measurements.Comment: 9 pages, 8 figure

Cross-Sections of Large-Angle Hadron Production in Proton- and Pion-Nucleus Interactions III: Tantalum Nuclei and Beam Momenta from +/-3 Gev/c to +/-15 Gev/c

We report on double-differential inclusive cross-sections of the production of secondary protons, charged pions, and deuterons, in the interactions with a 5% nuclear interaction length thick stationary tantalum target, of proton and pion beams with momentum from +/-3 GeV/c to +/-15 GeV/c. Results are given for secondary particles with production angles between 20 and 125 degrees. They are of particular relevance for the optimization of the design parameters of the proton driver of a neutrino factory.Comment: 68 pages, 12 figures, corrections in v2: added 'HARP -CDP group' to author name, corrected two typos in Table 4 (last two p values for 65-90 degrees were all 0.972