[en] The Dyson-Schwinger approach to mesons as quark-antiquark bound states produces a very satisfactory description of the whole light pseudoscalar nonet, both at zero and at finite temperatures [1]. Especially interesting is the temperature behavior of the η-η′ complex, where results for masses differ very greatly for various possible relationships between the chiral restoration temperature and the temperature of melting of the topological susceptibility χ. Namely, χ is connected with the quantity β in the η-η′ mass matrix as χ = β (2 +X ²)f²_π/6, where $X=f_{\mathrm{\pi <!--\; ??\; -->}}/f_{s\stackrel{¯<!--\; ??\; -->}{s}}$. For example, in certain regimes, the “mass” of η _NS , namely $M_{{\mathrm{\eta <!--\; ??\; -->}}_{NS}}$, for some temperatures becomes larger than $M_{{\mathrm{\eta <!--\; ??\; -->}}_{NS}}$, the “mass” of η _S [1]; that is, $M_{{\mathrm{\eta <!--\; ??\; -->}}_{NS}}$ and can $M_{{\mathrm{\eta <!--\; ??\; -->}}_{NS}}$ can cross.

[en] Optical diagnostics is widely used, both in plasma-physics experiments and in measuring parameters of electron and positron beams in accelerators. In doing so, the approaches with the same methodological base are often applied, which is explained by similarity of certain properties of objects under study despite the fact that these fields of physics are absolutely specific and require using the specialized techniques. The possibility of close contacts and cooperation among scientists concerned with similar problems in different fields of physics contributes to the fruitful exchange of ideas and helps to overcome these problems. It is especially characteristic of the Budker Institute of Nuclear Physics, Siberian Branch of Russian Academy of Sciences, which is famous for pioneering works in the field of electron-positron colliders and controlled thermonuclear fusion. The first part of this paper presents a review of optical diagnostics of the stationary beam parameters in cyclic accelerators of electrons and positrons. The only techniques considered are those that became the recognized tools at colliders and storage rings of the latest generation, without which the routine operation of the facility is difficult to imagine. The second part of the paper describes optical diagnostics used in experiments of heating the plasma by a high-current electron beam.

[en] The paper presents several recent ATLAS results on the analyses of B-meson decays into charmonium states. These include the measurements of B⁺ mass and the fractions of J/ψ mesons produced in b-hadron decays in pp collisions at $\sqrt{s}$ = 13 TeV in the center of mass system. The measured partial widths and polarizations in B⁺ _c → J/ψD^(*)+ _s decays and CP-violation parameters in B⁰ _s → J/ψϕ decays in pp collisions at 7 and 8 TeV in the center of mass system are also presented.

[en] Double Chooz is a short-baseline neutrino disappearance experiment. It detects ν̄ _e produced in the power plant of Chooz, France, where is located. The main goal of the experiment is the measurement of θ₁₃ mixing angle and in 2011 for the first time the experiment observed an indication for a non zero value of such an oscillation parameter. The mixing angle was successively measured using only the far detector finding the best fit value of sin²(2θ₁₃) = 0.090^+0.032_−0.029 . The near detector is under construction and will start data taking by the middle of 2014 allowing the reduction of the systematic errors. In this paper I make a review of the Double Chooz experiment, focusing in particular on the latest results of the measurement of the mixing angle θ₁₃ relying on the neutron absorption on Gadolinium. I also present results proving the capability of Double Chooz to identify the ortho-positronium. This has been done in an event-by-event basis for the first time in a large liquid scintillator experiments, and can be an additional handle for the electron/positron discrimination in future detectors based on such technology.

[en] The article presents the relevance and advantages of the new gamma observatory TAIGA (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy), which is being constructed in the Tunka Valley 50 km from Lake Baikal. Various detectors of the six TAIGA gamma observatory arrays register the Cherenkov and radio radiation, as well as the electron and muon components of EAS. The primary objective of the TAIGA gamma observatory is to study the high-energy part of the gamma-ray spectrum, in particular, in order to search for Galactic PeVatrons. The energy, direction, and position of the EAS axis are reconstructed in the observatory based on the data of the wide-angle Cherenkov detectors of the TAIGA-HiSCORE experiment. Taking into account this information, the gamma quanta are distinguished from the hadron background using the data obtained by the muon detectors and telescopes that register the EAS image in the Cherenkov light. In this hybrid mode of operation, the atmospheric Cherenkov telescopes can operate in the mono-mode, and the distance between them can be increased to 800–1000 m, which makes it possible to construct an array with an area of 5 km² and more at relatively low cost and in a short time. By 2019, the first stage of the gamma observatory with an area of 1 km² will be constructed; its expected integral sensitivity for detecting the gamma radiation with an energy of 100 TeV at observation of the source for 300 hours will be approximately $2\times <!--\; ??\; -->5$ 10^–13 TeV cm^–2s^–1.

[en] Presented are recent results of experiments on the SND detector. Data were collected on the VEPP-2000 and VEPP-2M $e^{+}{e}^{-<!--\; ???\; -->}$ colliders (Novosibirsk) in the c.m. energy region 0.3–2.0 GeV. Integrated luminusity used is 70 and 25 pb^–1 respectively. Cross section of the $e^{+}{e}^{-<!--\; ???\; -->}\to <!--\; ???\; -->{\mathrm{\pi <!--\; ??\; -->}}^0\mathrm{\gamma <!--\; ??\; -->},$ $e^{+}{e}^{-<!--\; ???\; -->}\to <!--\; ???\; -->{\mathrm{\pi <!--\; ??\; -->}}^{+}{\mathrm{\pi <!--\; ??\; -->}}^{-<!--\; ???\; -->}{\mathrm{\pi <!--\; ??\; -->}}^0\mathrm{\eta <!--\; ??\; -->},$ $e^{+}{e}^{-<!--\; ???\; -->}\to <!--\; ???\; -->\mathrm{\omega <!--\; ??\; -->}\mathrm{\eta <!--\; ??\; -->}{\mathrm{\pi <!--\; ??\; -->}}^0$ processes is measured.

[en] We review two off-shell models for spontaneously broken $\mathcal{N}=1$ and $\mathcal{N}=2$ supergravity proposed in arXiv:1702.02423 and arXiv:1707.07390. New results on nilpotent $\mathcal{N}=1$ supergravity are also included.

[en] The framework of scintillation counters for the CDF II muon system at the Tevatron collider at Fermilab is described. Information from the detectors of the muon system is essential for forming triggers of the first and second levels and for an “off-line” data analysis related to studies in the field of the heavy quark physics, Standard Model tests, search for phenomena beyond its limits, and for many other CDF II experiments with p $\stackrel{¯<!--\; ??\; -->}{p}$ collisions at the energy √s = 1.96 TeV.

[en] This review considers important properties of the top-quark. The top-quark decays before hadronization, and the spin information is directly transferred to the decay products. Therefore the structure of the weak interaction is investigated by measuring the helicity fractions, f, of the W boson—the top-quark decay product. Other investigations: search for the presence of V+A interaction, search for exotic top-quark charge — 4/3 and for $t\stackrel{¯<!--\; ??\; -->}{t}$ — resonances—all of them, so far, were not found in the experiments — testifies against of going out of the Standard Model.

[en] An expression for the free energy of an arbitrary static distribution of wedge dislocations in a solid is proposed. It represents a Euclidean version of (1+2)-dimensional gravity interacting with an arbitrary number of point particles. It is shown that the solution of the equilibrium equations leads to the Cauchy problem for effective equations determining the form of dislocations, while the problem of finding a metric leads to the Riemann-Hilbert problem for a frame with an $\mathbb{O}(3)$ monodromy representation.