Ашық рұқсат
Рұқсат берілді
Тек жазылушылар үшін
Том 86, № 2 (2023)
Articles
Search for New Resonances in Proton–Proton Interactions at 13 TeV
Аннотация
The results of searches for new resonances in the ATLAS experiment at the Large Hadron Collider (LHC) on the basis of data collected for proton–proton interactions at a collision energy of 13 TeV within the LHC operation period spanning 2015 and 2018 are considered.
296-309
New Basic Solvents for Liquid Organic Scintillators. Development of Nd-Loaded Scintillators on the Basis of Synthine–Pseudocumene Mixture
Аннотация
Synthine and T-6 propellant are studied as new basic solvents for creating liquid organic scintillators. The light attenuation length in these solvents (both those obtained from the manufacturer and those subjected to chromatographic purification on Al2O3) was measured along with the relative light yield of scintillators based on them. The chemical composition of synthine was determined by the method of chromato-mass spectrometry and UV spectrophotometry. A Nd-loaded scintillator (СТв 9 g/L) based on a synthine–pseudocumene mixture was created, and its light yield (LY 60%) was measured with respect to a scintillator based on linear alkyl benzene (LAB).
310-319
Structures of Weak-Mixing Matrices As a Consequence of Broken Mirror Symmetry
Аннотация
A model of symmetry breaking is described for a system that may spontaneously choose between a left-handed and a right-handed weak current. For a hierarchic structure of the fermion mass spectrum, this mirror-symmetric system permits reproducing all qualitative properties of the weak-mixing matrices for both quarks (CKM matrix) and leptons (PMNS matrix) without numerically adjusting model parameters. The hierarchy of the CKM matrix elements is directly related to the hierarchic mass spectrum of quark generations. Qualitative properties of the PMNS matrix arise in the case where the spectrum has an inverse character (@ is the smallest mass) and where the Standard Model neutrino is a Dirac particle. A relative smallness of the neutrino-mixing angle @ is due here to the smallness of @ and the smallness of the charged-lepton mass ratio
.
320-336
Nucleon–Nucleon Interaction As a Basis for Studying the Structure of Heavy Nuclei
Аннотация
A brief analysis of the development of theoretical approaches to describing the structure of heavy atomic nuclei is presented. Attention is given primarily to approaches based on nucleon–nucleon interaction. An approach relying on the use of a relativistic energy-density functional is considered. The results obtained by calculating binding energies and nuclear radii within chiral effective field theory are discussed.
337-344
Use of Global Predictions for Beta-Decay Rates in Astrophysical Models
Аннотация
The nucleosynthesis of heavy elements is calculated for two scenarios of neutron-star merger. Various global beta-decay models, including those based on the random-phase approximation (QRPA), relativistic quasiparticle RPA (pn-RQRPA), and the finite-amplitude method (FAM), were employed in these calculations. It is shown that the application of various global models in calculations of nucleosynthesis leads to the formation of a realistic structure of the curve of abundances of chemical elements. In contrast to nucleosynthesis in the scenario of merger of equal-mass neutron stars, the formation of elements in matter of the outer crust upon the explosion of a low-mass neutron star is weakly model-dependent in the region from the first to the second peak. However, the abundance of elements depends greatly on the beta-decay model in a strong r-process. No systematic effect of the beta-decay model on the results of nucleosynthesis is revealed.
345-352
Calculation of Neutron and Gamma Yields of (@, @) and (@,@) Reactions by Means of a New Version of the NeuCBOT Program for low background Experiments
Аннотация
(\(\alpha,n\)) и (\(\alpha,n\gamma\)) reactions induced by the alpha decays of uranium, thorium, and their daughter nuclides generate the intrinsic neutron and gamma backgrounds in modern ultralow background neutrino and dark matter detectors. In order to minimize the background, it is essential to select materials on the basis of a detailed analysis of relative concentrations of radionuclides and calculations of neutron and gamma-radiation yields. The NeuCBOT (Neutron Calculator Based On TALYS) program makes it possible to perform such calculations. The present article gives a review of a new version of the NeuCBOT program and a comparison of the results of calculations with different software tools.
353-360
Fragmentation of Nuclei under the Effect of Radiation of Various Types
Аннотация
An analytic approximation is proposed for a determination of the distribution of the inelastic energy loss of charged fragments originating from nuclear reactions induced by collisions of protons, photons, and electrons with silicon nuclei. It is shown that, in the energy range between 3 and 10 GeV, the effect of the hadronization process on this distribution for heavy secondary ions increases with incident-radiation energy. A strong asymmetry of the distribution calculated for collisions with relativistic electrons is indicative of a momentum transfer to only a small fragment of the nucleus involved.
361-368