Principle optical scheme of the neutrino beam production channel based on the accelerator complex U-70 is considered. In order to extract the required pulse interval of π-mesons, a two-magnetic system with a “field” lens with a one-way deflection of the parent particle beam and full compensation of the dispersion is proposed. In this scheme the decay part of the channel is deflected with respect to the direction of the primary proton beam aiming at the target. The main computational characteristics of the neutrino beam at the far detector at a distance of 2595 km from the end of the decaying part of the channel as well as the parameters of the parent π mesons at the beginning of the decaying part are discussed.

One of the main problems associated with the implementation of neutron capture therapy in clinical practice, requiring a solution, is the determination of absorbed dose. The only method that directly allows measuring the absorbed dose is gamma spectrometry, based on the registration of gamma rays with an energy of 478 keV. This article considers the possibility of using a xenon gamma spectrometer, which has high radiation resistance to neutron fluxes. The GEANT4 software package was used to study the neutron capture therapy process and conduct corresponding calculations.

A self-consistent method for studying second-order anharmonic effects in the framework of quantum many-body theory is used for the first time to calculate the probabilities of 𝐸1-transitions between the main and two-phonon [3−1 × 2+1 ]1−-state in semi-magical isotopes 104−124Sn. The approach used contains accounting for: 1) self-consistency between the nuclear mean field and effective interaction, based on the use of the energy density functional method with proven parameters of the DF3-a Fayans functional, 2) three-quasiparticle ground state correlations and 3) the effects of nuclear polarizability. Good agreement was obtained with the available experiments, including 112Sn. The values of 𝐵(𝐸1) are predicted for even-even nuclei 104−110,114Sn. It is shown that the new, i.e. dynamic three-quasiparticle ground state correlations make a very significant contribution to the reduced probabilities of such 𝐸1-transitions and their consideration is necessary to explain the experiment.

In this work, the equations of quantum relativistic hydrodynamics are obtained from the effective Klein–Fock–Gordon equation taking into account dissipation. Taking into account dissipation in the Klein–Gordon equation leads to the need to introduce an additional thermal term and an equation for it. As a result, a closed system of equations was obtained taking into account non-equilibrium processes, which makes it possible to describe the dynamics of the process of collisions of atomic nuclei and calculate the yield of secondary particles. Solving the resulting equations makes it possible to identify quantum shock waves and the time evolution of the resulting hot spot. The calculated spectra of emitted protons in heavy ion collisions are compared with available experimental data.

The possibility of refining the energy of the nuclear isomer 229mTh with the energy of 8.36 eV, the most likely candidate for the role of a nuclear frequency standard, using resonant optical pumping is discussed. Attention is focused on the broadening of theresonance in order toreduce scanning time. The proposed twophoton method uses radical broadening of the isomer line due to mixing with an electronic transition. This method is not burdened by cross-section reduction, in contrast with internal-conversion-based resonance broadening or intended extra-broadening of the spectral line of a scanning laser. In the case under consideration, it turns out to be two orders of magnitude more effective. It applies to both ionized and neutral thorium atoms. The realization of the method supposes excitation of both the nucleus and the electron shell in the final state.

In the framework of the Standard Model, the values of branching ratios and differential distributions for four-lepton decays 𝐷𝑠− → µ+µ−¯ν𝑒 𝑒− and 𝐷𝑠− → 𝑒+𝑒−¯νµ µ− are found. In our calculations we took into account the processes of a virtual photon emission by 𝑠- and 𝑐-quarks of the 𝐷𝑠−-meson and bremsstrahlung. The emission of a virtual photon by 𝑠-quark have been described using the vector mesons dominance model.

The explicit expression for the probability of absorption of a twisted photon by an atomic nucleus has been obtained. It is shown that photoabsorption obeys the selection rule 𝑗 > |𝑚γ|, where 𝑗 is the multipolarity of the nuclear transition, when the nuclei lie near the axis along which a twisted photon with a projection of the total angular momentum 𝑚γ propagates. In the long-wave limit, the main contribution to the probability of absorption of a twisted photon comes from the multipole transition with 𝑗 = |𝑚γ|. The absorption coefficient for twisted photons in a target consisting of many nuclei has been found.

Interest to processes of multiparticle production in lepton and hadron interactions is not decreased. Development of strong interaction theory, quantum chromodynamics, allowes describing of these interactions at the quark-gluon level. Transit from partons to observable hadrons at the hadronization stage is extremely difficult. This paper presents the gluon dominance model that describes multiparticle production of secondary particles including the hadronization stage. This model is applied to the description of 𝑒+𝑒−- annihilation. It confirms the active role of the gluon component at the secondary particle formation, evidences about fragmentation mechanism of hadronization, which is realized in vacuum, describes multiplicity distribution data.

The 𝑒+𝑒− → 𝑛𝑛 cross section was measured at energies from the threshold to 1908 MeV in the center of mass (c.m.). The experiment to measure the cross section has been carried out at the VEPP-2000 𝑒+𝑒− collider in 13 energy points. The SND detector is used to detect the produced neutron-antineutrons (𝑛𝑛) events. A special time measurement system on the calorimeter was used to select the time-delayed 𝑛𝑛 events. The measured 𝑒+𝑒− → 𝑛𝑛 cross section is 0.4–0.6 nb. The neutron effective timelike form factor in the energy range under study varies from 0.3 to 0.6.

The main goal of the SPASCHARM experiment is the systematic study of spin phenomena at intermediate energies. For this purpose, it is planned to create a beam of polarized protons and antiprotons. The research includes, among other things, the study of elastic scattering. Some of the required equipment for polarimetry is planned to be used to study also elastic scattering immediately after the creation of such a channel. In this work, a set of observables necessary for model-free reconstruction of elastic proton-proton scattering amplitudes is investigated and determined.