Abstract In this paper, we present a feasibility study of the first measurement of the longitudinal polarization of a muon from the \(\tau\)-lepton decay to extract the Michel parameter \(\xi^{\prime}\) at the future Super Charm-Tau Factory (SCTF). The expected number of \(\mu^{-}\to e^{-}\nu_{\mu}\bar{\nu}_{e}\) events on the full SCTF data was estimated, possible background processes were studied

Abstract The process \(e^{+}e^{-}\to\eta\pi^{0}\gamma\) is studied in the range of center-of-mass (c.m.) collision energies between 1.05 and 2.00 GeV on the basis of data corresponding to an integrated luminosity of 94.5 pb\({}^{-1}\) that were accumulated in an experiment with the SND detector at the VEPP-2000 \(e^{+}e^{-}\) collider. The cross section for this process was measured for the first time

Abstract The differential spectra of final particles in the reaction \(pn\to pp\pi^{-}\) are presented according to data obtained at nine energy values with the aid of a deuterium-filled bubble chamber. These spectra are compared with the results of a partial-wave analysis of data obtained with a continuous neutron beam incident to a proton target. This analysis was used as basis for performing a global

Abstract Hadron form factors are calculated using the Lorentz-contracted wave functions, determined in the arbitrary dynamical scheme with the instantaneous interaction. It is shown that the large \(Q\) asymptotics of the form factors is defined by the contraction coefficient \(C_{m}(Q^{2})=\frac{m}{\sqrt{(}m^{2}+Q^{2}/4)}\), where \(m\) is the meson mass, and weakly depends on the interaction used

Abstract This paper presents \(W^{\pm}/Z\) cross section ratio predictions for the \(W\) and \(Z\) boson productions in their subsequent electron decay channels with next-to-leading order (NLO) and next-to-next-to-leading order (NNLO) calculations in perturbative QCD. The predicted ratios from the fiducial cross sections are primarily compared with the ATLAS measurement based on 13 TeV LHC proton–proton

Abstract New upper limits on the intrinsic-charm contribution to the proton are obtained on the basis of experimental data on the existence of pentaquarks involving a hidden charm. Possible distributions of heavy quarks within the proton are analyzed.

Abstract This article, presented on behalf of the Compact Muon Solenoid (CMS) Collaboration, gives a generalizing survey of the results of the CMS experiment that concern searches for Kaluza–Klein excited states of the graviton (KK modes) and for microscopic multidimensional black holes, quantum black holes, and string balls within multidimensional low-energy gravity. The present analysis relies on

Abstract The possibility of neutron generation by irradiating deuterated crystalline structures with an electron beam with an energy of 20–40 keV was studied. As targets, the deuterated crystalline structures of palladium and textured CVD diamond were used. Measurements of neutron emission are presented, which were carried out by three independent methods—scintillation detectors, counters based on

Abstract We propose a renormalizable Standard Model extension based on \(\Delta(54)\) symmetry which successfully accommodates the recent experimental values of the physical observables of the quark sector, including six quark masses, three quark mixing angles and the CP violating phase in the quark sector.

Abstract The differential cross sections for alpha-particle emission at an angle of 0\({}^{\circ}\) in the reactions induced by a 6-MeV/nucleon \({}^{56}\)Fe beams incident to \({}^{238}\)U and \({}^{181}\)Ta targets were measured versus the alpha-particle energy by means of a high-resolution magnetic analyzer (MAVR setup). The resulting spectra were found to contain fast alpha particles of energy

Abstract Measurement of the effective weak mixing angle \({\theta_{\textrm{eff}}}\) in an experiment at the Super Charm Tau Factory is discussed for the case of a longitudinal polarization of electrons. A method for measuring the average electron beam polarization by means of analyzing the differential cross section for the decay process \({{J/\psi}}\to[\Lambda\to p\pi^{-}][{\bar{\Lambda}}\to{\bar{p}}\pi^{+}]\)

Abstract CP-symmetry violates in oscillations of neutrinos in vacuum in presence of three generations. In this case there is an inherent complex phase in PMNS-matrix. When any two neutrino masses degenerate the CP-violation vanishes. In the present article different mechanisms of CP-symmetry recovery are demonstrated in case of two degenerate neutrino mass-states.

Abstract Fundamentals of boron neutron capture therapy of malignant tumors are outlined, and the current status of the development of epithermal-neutron sources on the basis of charged-particle accelerators is surveyed. Attention is additionally given to a neutron source based on a charged-particle accelerator belonging to a new type—a tandem accelerator with vacuum insulation and a lithium neutron-producing

Abstract Parameterizations of the electromagnetic form factors of \(f_{1}(1285)\) meson are considered. Using these parameterizations theoretical predictions for the total cross section of the direct \(f_{1}(1285)\) meson production in \(e^{+}e^{-}\) annihilation, \(\sigma(e^{+}e^{-}\to f_{1}(1285))\), are obtained.

Abstract Results of searches for signals from new physics beyond the Standard Model in proton–proton collisions at the c.m. energy of \(\sqrt{s}=13\) TeV are surveyed. Dilepton-production events detected by the CMS experiment during Run 2 of the Large Hadron Collider (LHC) are used in these searches. The total amount of the data under analysis corresponds to an integrated luminosity of up to 140 fb\({}^{-1}\)

Abstract Investigation of properties of nuclear matter at extremely high temperature and/or extremely high baryon densities under laboratory conditions is one of the fundamental lines of research in high-energy physics. Throughout the past decades, such investigations have been performed in collisions of ultrarelativistic heavy ions in several experiments at modern accelerator complexes, including

Abstract The convergence of bound-state calculations performed via the oscillator basis expansions by means of locating \(S\)-matrix poles for bound states within the HORSE and SS-HORSE approaches is examined. The convergence in question is studied both in the case of a sharp truncation of the potential matrix in the harmonic-oscillator space and in the case of smoothed matrix elements of the potential

Abstract In an experiment with the SND detector at the VEPP-2000 \(e^{+}e^{-}\) collider, the cross sections for the processes \(e^{+}e^{-}\to K^{+}K^{-}\pi^{0}\) and \(e^{+}e^{-}\to\phi\pi^{0}\) were measured at collision energies of \(\sqrt{s}=1.28{-}2.00\) GeV in the center-of-mass frame. The results agree with the results of earlier measurements in the BABAR experiment and have a commensurate precision

Abstract The process \(e^{+}e^{-}\to\omega\pi^{0}\to\pi^{+}\pi^{-}\pi^{0}\pi^{0}\) was studied in the energy range between 1 and 2 GeV to the best precision in the world. The data used correspond to an integrated luminosity of \(35\text{ pb}^{-1}\) accumulated with the SND detector at the VEPP-2000 \(e^{+}e^{-}\) collider. The statistical accuracy of the measured cross section is 2 to 22\(\%\), whereas

Abstract The present article gives a brief account of some interesting results obtained most recently in studying heavy-ion physics—in particular, quark–gluon matter—with the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC).

Abstract NOvA is a neutrino experiment deployed at Fermi National Accelerator Laboratory (FNAL, USA) and designed for studying oscillations—namely, the appearance of electron neutrinos and the survival of muon neutrinos. Two detectors, a near and a far one, are separated by a distance of 810 km and are positioned at an angle of 14 mrad with respect to the axis of a beam from the NuMI accelerator complex

Abstract A new ion identification method for accelerator mass spectrometry on the basis of measuring ion track ranges is proposed. A low pressure time projection chamber (TPC) with charge readout by means of a thick gas electron multiplier (THGEM) was developed for testing this method. Tracks of alpha particles from various radioactive sources were successfully recorded by this TPC. In particular,

Abstract The international accelerator neutrino experiment T2K (Tokai-to-Kamioka) began accumulating data in 2010 and has since then accomplished 10 runs in the neutrino and antineutrino modes. The present article reports on the latest results following from the analysis of these data and including the first ever 3\(\sigma\) constraints on the CP-violating phase \(\delta_{CP}\). Also, the plans for

Abstract The results obtained in the CMS experiment at the Large Hadron Collider (LHC) by studying electroweak interaction are surveyed.

Abstract The electromagnetic CsI(Tl) calorimeter is one of the key systems in the Belle II detector. The calorimeter is aimed primarily at efficiently detecting photons over a wide energy range from several tens of MeV units to \(7\) GeV. A highly efficient data acquisition system is required for a continuous readout of signal events at a trigger rate corresponding to the maximum collider luminosity

Abstract An exact formula that relates standard \(\zeta\) functions and so-called hatted \(\zeta\) (\(\hat{\zeta}\)) functions in all orders of perturbation theory is presented. This formula is based on the Landau–Khalatnikov–Fradkin transformation.

Abstract The Levinson theorem relates the difference of the phase shifts at the threshold and at infinity to the number of bound states. The theorem is modified in view of the fact that Castillejo–Dalitz–Dyson (CDD) poles and Jaffe–Low primitives corresponding to zeros of the \(D\) function on the unitary cut are present in the scattering amplitude. It is shown that, in general, the difference of the

Abstract This study probes the backbending phenomena in even–even \({}^{162{-}172}\)Hf isotopes. Experimental ground-state rotational energies up to \(J^{\pi}=36^{+}\) states were used to calculate the variation of the moment of inertia against the square of rotational angular frequency. The result shows that the calculated values of the moment of inertia for heavy mass isotopes; \({}^{170}\)Hf and

Abstract There was a lot of puzzles in the history of the discovery and investigations of the muon itself and the muon component of cosmic rays. The last of them is an excess of high-multiplicity muon groups that grows with increasing energy of primary cosmic rays and which is detected in various experiments. An excess of muons that have ultrahigh energies (above 100 TeV) is the second aspect of the

Abstract The total kinetic energy as a function of fragment mass (TKE/A) was calculated for photofission of \({}^{232}\)Th, \({}^{234}\)U, \({}^{238}\)U, \({}^{240}\)Pu, and \({}^{242}\)Pu using a systematic statistical scission point model. In the proposed systematic method, all the energies involved in fission need to be expressed as a function of mass and atomic numbers of fission fragments. Therefore

Abstract A preliminary result of an analysis of the process \(e^{+}e^{-}\to K_{S}K^{\pm}\pi^{\mp}\) whose cross section was measured in the range of center-of-mass collision energies between 1.2 and 2 GeV is presented. The analysis is based on the data sample corresponding to an integrated luminosity of about 120 pb\({}^{-1}\) accumulated with the CMD-3 detector at the VEPP-2000 electron–positron collider

Abstract The first cycle of measurements of the ratio of cumulative spectra of beta particles originating from the isotopes \({}^{235}\)U and \({}^{239}\)Pu undergoing thermal-neutron-induced fission was performed. It is found that the curve obtained from our present measurement of the \({}^{235}\)U\(/^{239}\)Pu ratio of beta-particle spectra lies 5\({\%}\) lower than the analogous curve following

Abstract Investigation of lepton propagation through matter is of importance for cosmic-ray physics and neutrino astronomy. The diffractive scattering of virtual photons is considered as a process that leads to the energy loss of leptons emitting these photons. The interference between this process and bremsstrahlung makes a contribution that depends on the sign of the lepton charge.

Abstract Possible strategies of the development of low-energy nuclear physics in Russian Federation on the basis of the DERICA (Dubna Electron–Rare Isotope Collider fAcility ) project is examined. DERICA is a multiuser multipurpose facility for the production and study of radioactive isotopes (RI). In the research program of DERICA, emphasis is placed on studying RI in collector rings, but a stage-by-stage

Abstract For further advances to be made in theoretically describing QCD processes at high energies and bounded momentum transfers, it is necessary to understand the structure of three-Reggeon cuts and to be able to calculate their contributions to QCD amplitudes. At the present time, the theory of such cuts is still in its infancy. The existing approaches to calculating contributions of three-Reggeon

An Erratum to this paper has been published: https://doi.org/10.1134/S1063778820120030

Abstract First, the case of (0 + 1)-dimensional nonequilibrium quantum mechanics is analyzed using the Yukawa model in external scalar field \({{\phi }_{{{\text{cl}}}}}(t) = \frac{m}{{{\lambda }}} + \frac{{{\alpha }}}{{{\lambda }}}t\) as an example. It is shown that the exact fermion propagators do not change with time, and the growth of bosonic propagators is determined by the contribution to the

Abstract The phase diagram of quantum chromodynamics under different external parameters, such as the temperature, baryon chemical potential, and magnetic field strength, is studied using the method of lattice supercomputer simulation. The calculations are carried out with three light quarks u, d, and s using an imaginary chemical potential. The results for real values of chemical potential μ are obtained

Abstract In this paper, we report the characteristics of the generated beams, the extracted electron beam and the beam of secondary electrons/positrons, of the LPI accelerator complex Pakhra as of November 2019 for testing and calibrating detectors used in large accelerator and astrophysical experiments. At energies of 250–500 MeV of the electron beam ejected into Hall 1 from the S-25R synchrotron

Abstract Scintillation properties of crystals based on complex oxides of group 3 elements such as Y3Al5O12:Ce, Y3Al5O12:Sc, Y3Al5O12:Re, Y3Al5O12:Sc:La, YAlO3:Ce, YAlO3:Ce:Yb, YAlO3:Ce:Sc, YAlO3:Eu, YAlO3:Re, YAlO3:Ti, and YAlO3:Ce:Ti are studied. Crystals based on complex oxides of group 3 elements have high thermal shock resistance and high corrosive resistance. These crystals have good temporal

Abstract A variant of the proton beam delivery system with an energy of 60 MeV for the future oncological ophthalmological center for proton radiation therapy at the isochronous cyclotron C-80 at PNPI was designed. The requirements to the beam characteristics were defined. On the basis of a series of calculations, the optimal parameters and composition of the beam line elements were determined. It

Abstract The paper describes the results of post-irradiation examinations for pressurized specimens that varied in design and were made of austenitic steels 08Х18Н10Т and 07Х16Н12М3Т. They were under irradiation testing in the BOR-60 reactor to attain different damage dose values. The contribution of irradiation creep to the overall change in diameter was studied. Irradiation creep moduli data were

Abstract The paper considers the effects produced by arranging a lead cavity in the central part of a lead-cooled fast reactor core. It is shown that the most favorable effect from the presence of an inner lead cavity at the center of the core can be obtained when radiogenic lead with a dominant 208Pb isotope content is used as the material of the cavity, coolant, and neutron reflector. This is explained

Abstract Using the equation of state, on the basis of perturbation theory, the thermophysical properties of the main combustion products N2, O2, CO2, and H2 of organic substances are calculated under normal conditions and in the region of high pressures. The method of calculating the viscosity of individual substances based on the Chapman–Enskog equation using the values of the radial distribution

Abstract Results of a study of the electronic structure and optical properties of a novel material based on thin films comprised of Mo nanoclusters obtained by gas-phase magnetron sputtering are presented. The chemical composition of the obtained films immediately after deposition (in situ) and upon exposure to the atmosphere (ex situ) was investigated by X-ray photoelectron spectroscopy. It is shown

Abstract Nowadays, graphene physics is aimed at finding a way to control the band gap of graphene, which is necessary for application of graphene in nanoelectronics. The purpose of this work is to investigate the systems that break an inversion symmetry of a hexagonal lattice. The electronic properties of armchair and zigzag graphene nanoribbons are obtained and the dependence of the electronic properties

Abstract As the burnup increases, the requirements of nuclear and radiation safety for spent nuclear fuel (SNF) at the subsequent stages of operation grow. The analysis and estimation of the required cooling time of the spent fuel assemblies (SFAs) of the VVER-1200 reactor for transportation in various types of transport containers (TUK-13 and TUK-141O) are performed. The estimates are based on the

Abstract The changes in physicochemical parameters such as specific resistance, viscosity, density, and formation of gaseous products H2, CH4, C2H4, C2H6, C3H8, C4H10, C5H12, and C6H14 with respect to the adsorbed dose in the interval of 29.7–237.6 kGy are studied. It is established that the chemical composition of transformer oil changes under the action of γ irradiation, which is accompanied by the

Abstract The cross sections of neutrino absorption by the gallium-71 nucleus are obtained for neutrinos from artificial 37Ar, 51Cr, and 65Zn sources. The calculations rely on the new measurement of the energy threshold of this absorption reaction, and contributions of germanium-71 excited states to the total cross section are estimated by invoking the data on the 71Ga(3He,t)71Gе charge-exchange reaction

Abstract The charge-exchange reaction \({{\pi }^{ - }}p \to n\omega (783)\phi (1020)\), \(\omega \to {{\pi }^{ + }}{{\pi }^{ - }}{{\pi }^{0}}\), \(\phi \to {{K}^{ + }}{{K}^{ - }}\) is studied on the upgraded VES facility (U-70, Protvino) upon the interaction of a 29 GeV/c meson beam with a beryllium target. There are 905 events of the \(\omega \phi \) system selected. The distribution over the invariant

Abstract MoS2 nanofilms were created by thermochemical processing (sulfurization) of thin-film Мо and МоОу precursors in S vapor. The precursor films were created by pulsed laser deposition. The obtained molybdenum disulfide films consisted of 2H-MoS2 nanocrystals with laminar packing of basal planes oriented perpendicular to the film surface. The increase in the sulfurization temperature from 500°C

Abstract The results of mechanical and electrodynamic calculations of a frequency tuner for the half-wave superconducting resonator operating at 325 MHz and a relative speed of 0.21 for the Nuclotron-NICA mega-science injection facility are presented. The tuner compensates for the resonance frequency drift caused by external factors. Methods for tuning the frequency of half-wave resonators are considered

Abstract This article discusses modernization of the HIPr accelerator for irradiation of tungsten samples with a 10 × 10 mm form factor aimed at simulating radiation induced defects. The measurement system of the beam current is developed for experiments on target irradiation. The simulation results of beam transport in the accelerator output channel are presented with the measurements of beam transversal

Abstract The study considers diffraction radiation, which is excited when an electron moves near a cluster of two interacting subwavelength particles. The interaction is manifested in the fact that the radiation field from each particle is determined not only by the external field of the electron, but also by the field of the neighboring particle. Based on the obtained expressions for the radiation

Abstract The results of the formation of an original material based on thin films of metal nanoclusters and the investigation of its chemical composition, surface morphology, and structure are presented. Monodisperse thin films comprised of individual nanoclusters of Ta, Mo, and Ni metals were manufactured by gas-phase magnetron sputtering. Images of the surface were obtained by scanning electron microscopy

Abstract In this paper, we describe a small-size magnetic spectrometer of electrons that allowed studying the spectral composition of electron emission in the energy range of 5–400 keV from a micropinch discharge plasma using a low-inductance vacuum spark setup.

Abstract The use of microwave heating to produce solid solutions of actinide oxides in the processes of thermal denitration of model nitric acid solutions formed in reducing stripping schemes at the final stages of the PUREX process, containing U and Th (Pu simulator) and unreacted reducing agents (hydrazine, etc.), is proposed. As a result, after quantitative distilling of water vapor, acid, and volatile

Abstract The processes of erosion and redeposition of plasma-facing materials in fusion devices are some of the most important factors affecting the plasma parameters and the resource of the first wall. The method of analyzing thin layers on a surface using keV-energy proton scattering expands the functionality of determining the rate of erosion and deposition of layers with a large atomic number on

Abstract Two technological schemes are considered, as well as the possibilities of their implementation for the manufacture of sealed accelerator tubes based on diodes with magnetic isolation Schematic designs of tubes under development with a laser source of deuterons and an electronic conductivity suppression system are presented. To do this, a sufficiently heat-resistant permanent magnet is included

Abstract Determining the centrality of a collision, or the impact parameter, in heavy-nucleus collisions is important for the analysis of all experimental data and their comparison with theory. One of the methods for this is to measure the number of spectators using a hadron calorimeter arranged at a small angle to the nuclear beam. It is shown that the accuracy in determining the impact parameter