Hyperon appearance in neutron star matter within Skyrme approach and relativistic mean field theory
Hyperon appearance in neutron star matter within Skyrme approach and relativistic mean field theory
S. A. Mikheev$^{1,2}$, D. E. Lanskoy$^1$, A. I. Nasakin$^{1,2}$, T. Yu. Tretyakova$^{1,2}$
Density at which the appearance of hyperons becomes energetically favorable is an important property of neutron star matter. Within two theoretical approaches, namely the nonrelativistic Skyrme model and relativistic mean field theory, we study how this characteristic depends on the properties of the hyperon–nucleon interaction. We show that the density of hyperon appearance strongly correlates with the contracting power of the hyperon–nucleon interaction, a quantity that characterizes the ability of a hyperon to polarize (compress or expand) the nucleonic core of a hypernucleus.
Show AbstractDependence of photoelectron angular distributions on the magnitude of hyperfine interaction in hydrogen-like targets in a pump-probe scheme
Dependence of photoelectron angular distributions on the magnitude of hyperfine interaction in hydrogen-like targets in a pump-probe scheme
K. A. Gnedovskaya$^1$, M. M. Popova$^2$, A. N. Grum-Grzhimailo$^2$, E. V. Gryzlova$^2$
In the paper, we examine the ionization of a hydrogen-like target in a pump-probe scheme. We analyze the polarization of the target during pumping its levels with total angular momentum of the electron shell 1/2 and 3/2 by a linearly or circularly polarized field. We examine the extent to which the polarization of the prepared (pumped) state can degrade due to hyperfine interactions. Depolarization itself is a phenomenon that manifests itself in a wide variety of processes. This work examines the manifestation of depolarization in the angular distributions of photoelectrons during subsequent ionization by a field also polarized linearly or circularly (with helicity equal or opposite to the pump field).
Show AbstractEstimation of the charging efficiency of micron-sized aluminum particles in an electrostatic injector
Estimation of the charging efficiency of micron-sized aluminum particles in an electrostatic injector
S. S. Avtorin$^{1,2}$, S. A. Bednyakov$^1$, O. M. Marchenko$^1$, N. B. Akimov$^1$, O. B. Dzagurov$^1$, O. P. Glotov$^1$, C. N. Gavrilovich$^{1,2}$
The correct assessment of the risks of reducing or losing the functionality of the open surfaces and instruments of the spacecraft is based, inter alia, on laboratory tests of the resistance of the relevant materials to the impact of particles simulating the flow of solid particles in laboratory conditions. In this work, the charge spectrum of PAP-1 aluminum dust particles was obtained using a stand consisting of an electrostatic injector, a parameter control unit, and a research chamber. The experimental spectrum was also correlated with the theoretical one. The distributions of such physical parameters of particles as size, velocity, and mass are obtained.
Show AbstractCharged-particle pseudorapidity and centrality distributions in Pb--Pb collisions at 5.36 TeV in the HYDJET++ model and comparison with LHC data
Charged-particle pseudorapidity and centrality distributions in Pb--Pb collisions at 5.36 TeV in the HYDJET++ model and comparison with LHC data
V. S. Bratyshev$^1$, D. A. Myagkov$^{1,2}$, S. V. Petrushanko$^{2,3}$
This work presents a comparison of the CMS experimental data on charged-particle pseudorapidity and centrality distributions in Pb--Pb collisions at record energy 5.36 TeV at the LHC with the results obtained from the HYDJET++ Monte Carlo generator using simulation with its default settings.
Show AbstractNew observables in momentum space for studying correlation effects in heavy ion collisions
New observables in momentum space for studying correlation effects in heavy ion collisions
E. -. Dlin$^1$, O. -. Teryaev$^{2,3}$
The results of modeling Au+Au collisions at 9.2 GeV energy within the Parton-Hadron-String Dynamics (PHSD) model are presented. New observables in momentum space – momentum vorticity and momentum shear – are introduced, which can serve as indicators of hydrodynamic behavior of quark-gluon plasma. Correlation effects, including the relationship between new observables and v2 flow and chirality, are investigated. It is shown that the proposed quantities allow indirect assessment of hydrodynamic characteristics of the system.
Show AbstractJet characteristics in pp collisions in events with Z-boson production
Jet characteristics in pp collisions in events with Z-boson production
M. S. Snarskaya, A. M. Anokhina
This work aims to compare the characteristics of events with a produced Z boson accompanied by jets, using open data from the ATLAS experiment and published results. The distributions of the jet multiplicity, emission angles, and transverse momentum are compared. These processes are important for refining the proton’s structure functions.
Show AbstractNeutral pion electroproduction off proton in reaction
Neutral pion electroproduction off proton in reaction
A. N. Pavlova$^1$, V. B. Ryzhkov$^1$, A. A. Rusova$^{1,2}$, E. L. Isupov$^2$
In this paper, the results of an analysis of events for the reaction e + p → e′ + p′ + π0 → e′ + p′ + γ + γ from the experimental data of the CLAS12 detector in the resonance region at an electron beam energy of Ee = 6.535 GeV are presented. A topology with the registration of two gamma quanta from the decay of a neutral pion in the final state is considered; special selections that reduce the number of background events are developed; a comparison is made between two Monte Carlo generators of reaction events: genKYandOnePion and MCEGENpiN radcorr V9b; an approximation of the distributions of the invariant mass of a photon pair in kinematic cells by the total energy of the final hadrons in the virtual photon - proton center of mass system W and the photon virtuality Q2 is carried out, based on which the reaction yields are calculated as functions of two variables; An assessment was made of the regions of kinematic variables available for extracting differential cross-sections.
Show AbstractPhenomenological Model of Solar Cyclicity
Phenomenological Model of Solar Cyclicity
I. Yu. Zobova$^{1,2}$, S. A. Krasotkin$^{1,2}$
This work presents a phenomenological model of solar cyclicity that integrates the secular, 11-year, and quasi-biennial variations of solar activity. Using a two-stage modi cation of the Singular Spectrum Analysis (SSA) method with window lengths of 132 months and 28 months, we performed a decomposition of the monthly mean total sunspot number (SSN) time series. An amplitude modulation of the 11-year and quasi-biennial variations by the secular cycle has been identifed, which allowed us to construct an additive-multiplicative model of the interrelations between the components of the series. A correlation has been found between the duration of the 11-year cycle and the rate of change of the secular variation 4.5 years prior to its onset. By applying an LSTM neural network for the secular cycle, approximating the 11-year cycle with a superposition of lognormal functions, and tting the quasi-biennial variations with a superposition of Airy functions, a forecast for the 25th solar cycle was produced. The forecast correlates with observational data with a determination coeffcient of R2 = 0.79. The results confirm the effectiveness of the proposed approach for modeling solar cyclicity.
Show AbstractAnalysis of inclusive differential cross sections of prompt isolated photon production in proton–proton collisions at the ATLAS detector
Analysis of inclusive differential cross sections of prompt isolated photon production in proton–proton collisions at the ATLAS detector
S. K. Klushin, L. N. Smirnova
The aim of this work is to study inclusive differential spectra of prompt isolated photon production in proton–proton collisions measured with the ATLAS detector at center-of-mass energies of 8 and 13 TeV.The analysis is based on published ATLAS experimental data available in the HEPData repository and processed using the ROOT software framework. The differential cross-section spectra are approximated by a power-law function, and the corresponding fit parameters are presented. A comparative analysis of associated production of prompt photons and Z bosons with hadronic jets (γ + jets and Z + jets) at a center-of-mass energy of 13 TeV is performed. The obtained values of the power-law exponents and the ratio of differential cross sections for Z bosons and prompt photons at high transverse momenta are in agreement with the predictions of quantum chromodynamics and the Standard Model of electroweak interactions.
Show AbstractResearch on vibration resistance of fiber and solid-state lasers
Research on vibration resistance of fiber and solid-state lasers
A. Yu. Danilov$^{1,2}$, G. Yu. Ivanov$^{1,3}$, E. A. Fomiryakov$^1$, A. V. Reznikov$^1$
Phase-frequency stability degradation under mechanical vibrations was characterized for single-frequency high-coherence fiber and semiconductor lasers. Vibration sensitivity showed strong dependence on both laser type (diode vs. fiber) and spatial orientation, with semiconductor devices demonstrating greater vibration resistance.
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