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Nucleon-Nucleon Interaction ib the Singlet State at Low Energy
No full textIt is possible to describe the scattering and the radiative capture with help of a Breit-Wigner resonance with negative energy
Angular Distributions of Emitted Electrons in the Two-Neutrino ββ Decay
No full textThe two-neutrino double-beta decay (2νββ-decay) process is attracting more and more attention of the physics community due to its potential to explain nuclear structure aspects of involved atomic nuclei and to constrain new (beyond the Standard model) physics scenarios. Topics of interest are energy and angular distributions of the emitted electrons, which might allow the deduction of valuable information about fundamental properties and interactions of neutrinos once a new generation of the double-beta decay experiments will be realized. These tasks require an improved theoretical description of the 2νββ-decay differential decay rates, which is presented. The dependence of the denominators in nuclear matrix elements on lepton energies is taken into account via the Taylor expansion. Both the Fermi and Gamow-Teller matrix elements are considered. For nuclei of experimental interest, relevant phase-space factors are calculated by using exact Dirac wave functions with finite nuclear size and electron screening. The uncertainty of the angular correlation factor on nuclear structure parameters is discussed. It is emphasized that the effective axial-vector coupling constant gAeff can be determined more reliably by accurately measuring the angular correlation factor
Higgs boson decay to paired : relativistic and one-loop corrections
No full textThe exclusive decays of the Higgs boson to and pairs are studied. The hard parts of the decay amplitudes are estimated within the perturbative Standard Model up to one-loop corrections. The soft fusion of heavy quarks to the quarkonium is described in framework of the relativistic quark model
Energy Spectra of Alpha Particles in the Interaction of Fe Nuclei with Tantalum and Uranium Nuclei at an Energy of 320 MeV
No full textThe differential cross sections for alpha-particle emission at an angle of 0 in the reactions induced by a 6-MeV/nucleon Fe beams incident to U and 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 corresponding to the two- and three-body exit reaction channels, including alpha particles of energy close to the two-body kinematical limit. The data obtained in this experiment were analyzed on the basis of the moving-source model. The emission of nonequilibrium alpha particles in the forward direction from the heavier target nucleus upon the complete or incomplete fusion of nuclei was revealed within the time-dependent quantum approach
Технологии баз данных. Проектирование реляционных баз данных: учебное пособие
No full textДанное издание продолжает серию публикаций, посвященную технологиямбаз данных, ориентированную на студентов бакалавриата и специалитета вузов,осуществляющих базовую подготовку выпускников в области информационныхтехнологий, программного обеспечения вычислительной техники и автоматизированных систем, программной инженерии и других смежных областей профессиональной деятельности. Первая книга из этой серии была посвящена введениюв технологии баз данных, в которой были освещены основные понятия, модели,архитектура баз данных. В первой книге уделено много внимания реляционнымбазам данных, но важнейшая тема — проектирование баз данных – подробноосвещена в этой книге. Доступный стиль изложения, направленность на эффективное сочетание теоретической и практической подготовки ИТ-специалистовявляются основными особенностями серии этих публикаций. Проектированиебаз данных является важнейшей составляющей проектирования и разработки информационных систем любого класса, так как базы данных являются ядром любой информационной системы, веб-приложения, мобильного приложения.Книга может быть полезна широкому кругу читателей, интересующихся данной тематикой. Для освоения материала необходимы знания модели данных,в том числе реляционной, и ее основных понятий, таких как отношение, атрибут,ключ, кортеж, степень, кардинальное число отношения, домен, схема отношения
Geodesic structure of the accelerated Stephani universe
No full textFor the Stephani cosmological model with accelerated expansion we investigate the main scenarios of the test particle motion. We show that within the area of the observable universe the singularities of the model do not influence the test particles motion. In accordance with the universe geometry, the observable velocities decrease by the cosmological expansion and the trajectories are represented by hyperbolas changing their curvatures with time