New highly granular neutrino detector SuperFGD for T2K experiment
New highly granular neutrino detector SuperFGD for T2K experiment
S. A. Fedotov, A. E. Dergacheva, N. V. Yershov, Yu. G. Kudenko, A. V. Mefodev, O. V. Mineev, D. V. Fedorova, M. M. Khabibullin, A. N. Khotjantsev, A. A. Chvirova
SuperFGD, a highly granular scintillator detector, is under final stage of construction to reduce systematic uncertainties in the T2K experiment in order to improve the sensitivity to CP-violation in neutrino oscillations. SuperFGD will be comprised of about 2×106 small (10×10×10 mm3) optically isolated polystyrene based plastic scintillator cubes with three orthogonal holes 1.5 mm in diameter. The readout of scintillating light from each cube is provided by three wavelength shifting fibers inserted into the three holes and coupled to Hamamatsu MPPC. The results of the study of scintillation elements of the SuperFGD detector, the results of charged particle beam tests at CERN of two prototypes of SuperFGD detector and plans for the final assembly of the detector and its installation at the experimental site are presented in this paper.
Show AbstractAerogel radiator for the Super Charm-Tau Factory
Aerogel radiator for the Super Charm-Tau Factory
A. A. Katcin$^{1,2}$, A. Yu. Barnyakov$^{1,3}$, M. Yu. Barnyakov$^{1,3}$, V. S. Bobrovnikov$^{1,2}$, A. R. Buzykaev$^1$, A. F. Danilyuk$^4$, S. A. Kononov$^{1,2}$, E. A. Kravchenko$^{1,2}$, I. A. Kuyanov$^1$, I. V. Ovtin$^{1,2}$, N. A. Podgornov$^{1,2}$, A. S. Shalygin$^4$
Particle identification system based on Focusing Aerogel RICH (FARICH) detector is considered as an option for the future experiments at the Super Charm-Tau Factory (Russia). New samples of focusing 4-layer aerogels with maximal refractive index 1.065 were produced in 2020–2021. First beam test results with relativistic electrons demonstrate single photon resolution (SPR) of 9-10 mrad. According to simulation results, the aerogels with such SPR are able to provide mu\pi-separation at the level of more than 3 standard deviations for tracks with momentum 1.5 GeV/c.
Show AbstractRare Semileptonic $B^+ \to \pi^+ \tau^+ \tau^-$ Decay within Perturbative QCD
Rare Semileptonic $B^+ \to \pi^+ \tau^+ \tau^-$ Decay within Perturbative QCD
I. M. Parnova, A. Y. Parkhomenko
Rare $B$-meson decays originated by flavor changing neutral currents (FCNCs), $b\to s$ and $b\to d$ quark transitions, are especially sensitive to New physics effects due to the smallness of their decay width. $B$-meson decays due to the $b\to s$ transition have been studied experimentally and theoretically, in a difference to $b\to d$ transitions, in particulear, the $B^+ \to \pi^+ \mu^+ \mu^-$ decay was observed by the LHCb collaboration in 2012 only. This decay is well studied theoretically and predictions are in agreement with experimental data obtained by same collaboration in 2015. It is also of interest to consider a similar decay, where a pair of tauons is chosen as the final pair of leptons. Theoretical predictions for the $B^+ \to \pi^+ \tau^+ \tau^-$ branching fraction are presented based on the effective electroweak Hamiltonian approach, depending on the choice of the parametrization of the formfactors entering the $B \to \pi$ matrix elements. A possibility of the $B \to \pi \tau^+ \tau^-$ observation at the LHC and SuperKEKB is discussed.
Show AbstractThe spatial resolution measurements of the Super charm-tau factory drift chamber small prototype
The spatial resolution measurements of the Super charm-tau factory drift chamber small prototype
I. Yu. Basok$^1$, A. V. Bykov$^1$, B. D. Kutsenko$^{1,2}$, D. A. Kyshtymov$^{1,2}$, V. G. Prisekin$^1$, K. Yu. Todyshev$^{1,2}$
The Budker Institute of Nuclear Physics is actively developing the Super charm-tau factory (SCTF) project, which is a mega-science class installation, that will be used to study rare c-quark and tau-lepton decays. The main part of a SCTF detector is a drift chamber, based on which the track reconstruction of charged particles is carried out. Accuracy of the trajectory reconstruction, i.e. a spatial resolution, is one of the main characteristics of the detector. This work is devoted to the experimental measurement of the spatial resolution on a drift chamber small prototype. The wire structure of the prototype consists of seven hexagonal cells that reproduce the cell of the first detector layer. The setup was calibrated during cosmic particles track reconstructions. In the work, the resolution of (97 ± 6) µm was obtained, and this demonstrates the possibility of obtaining the design parameters of the drift chamber based on the proposed wire structure. The results of this study were presented at the «Super c-tau factory» summer scientific school in Sarov in 2022.
Show AbstractAnalysis of the effect of gravity on the shape of the surface of a free liquid jet in an antenna element
Analysis of the effect of gravity on the shape of the surface of a free liquid jet in an antenna element
S. V. Khodyrev
The effect of gravity on the shape of the jet was taken into account. Based on the results obtained, mathematical modeling of its shape was performed, and later electromagnetic modeling of the antenna containing the resulting shape was performed. A comparative analysis of the results with the shape without taking into account gravity is made. From the comparison, an assessment of the effect on the characteristics of the antenna is given.
Show AbstractInfluence of training on the construction of evoked potentials
Influence of training on the construction of evoked potentials
A. О. Selskii$^{1,2}$, M. Yu. Novikov$^1$, K. S. Samatova$^1$, M. О. Zhuravlev$^{1,2}$
In the present work, a study of evoked potentials on the EEG of the human brain is carried out to compare people after training and at the first test. The test was a demonstration to the subject of an ambiguous object, in this case a Necker cube with different intensities of the sides. The subject had to evaluate the orientation of the cube and press the appropriate button: left or right. The purpose of this work is to determine how evoked potentials change when people are trained for this test. The group of subjects consisted of 21 people of different ages and genders. 11 of them have already passed the test with a similar design. The remaining 10 people faced such a test for the first time. For all subjects, evoked potentials were constructed for all EEG channels and the differences between these groups were shown.
Show AbstractCharacteristics of the current flowing through a semiconductor superlattice for different localization of a lattice defect
Characteristics of the current flowing through a semiconductor superlattice for different localization of a lattice defect
A. О. Selskii, O. I. Moskalenko, A. A. Koronovskii
The paper considers how the amplitude and frequency of current oscillations, as well as the form of current oscillations, change with a change in the localization of oscillations in the width of the conducting miniband. Semiconductor superlattices in the current fluctuation generation mode demonstrate frequencies up to several tens of gigahertz, which makes them promising transmitters in infocommunication data transmission systems. In this work, it is shown that the localization of the fluctuation of the fluctuation of the width of the conducting miniband strongly affects the characteristics of the current, while the influence of the fluctuation localization in the case of the presence of an inclined magnetic field and without it differs significantly. It is shown that a change in the miniband width in the last layer of the structure has a positive effect on the oscillatory characteristics of the current flowing through the superlattice in the absence of a magnetic field and negatively in the presence of an inclined magnetic field.
Show Abstractpplication of frequency-time analysis of signals for isolation of sleep stages
pplication of frequency-time analysis of signals for isolation of sleep stages
A. S. Akimova$^1$, M. O. Zhuravlev$^{1,2}$, A. E. Runnova$^{1,2}$
The paper is devoted to the study of possibilities of methods of frequency-time analysis of signals of the brain electrical activity for recognition of sleep stages on the example of clinical data of newborns monitoring. The division of newborns into gestational age groups and postnatal lifetime groups during monitoring showed how significant changes in brain activity in sleep and wakefulness in children of different groups, as well as significant variability and non-specificity of frequency-time characteristics of brain activity. Significance of tracking alpha-rhythm level in EEG motor cortex projection for premature children for separation of sleep and wakefulness states, as well as, possibly, as a marker of brain maturity in the early adaptation period is shown.
Show AbstractPropagation of electromagnetic radiation in graphene structures
Propagation of electromagnetic radiation in graphene structures
K. V. Bukhenskyy$^1$, A. B. Dubois$^1$, A. N. Konuhov$^1$, S. I. Kucheryavyy$^2$, A. S. Safoshkin$^1$
In this work, a mode method is developed for studying the processes of diffraction of an electromagnetic wave with a Gaussian intensity distribution on a planar structure "metal - nonlinear film (graphene) - semiconductor". The conditions for the excitation of a surface polariton are found depending on the geometry of the structure and the parameters of the Gaussian beam.
Show AbstractResearch into the holographic formation of chirped multilayer inhomogeneous PDLC diffraction structures under linear and nonlinear recording mode conditions
Research into the holographic formation of chirped multilayer inhomogeneous PDLC diffraction structures under linear and nonlinear recording mode conditions
V. O. Dolgirev, S. N. Sharangovich
This paper presents a research of the process of holographic formation of chirped multilayer inhomogeneous holographic diffraction structures in polymer encapsulated liquid crystals under conditions of linear and nonlinear recording modes. In the course of investigation it was found that under different modes of recording, lattice profiles could have two-dimensional inhomogeneity and differ from layer to layer, which was caused both by the influence of material absorption and change of period of holographic diffraction structure.
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