TAIGA-IACT: development of a new mirror alignment method and selection criterion of experimental data
TAIGA-IACT: development of a new mirror alignment method and selection criterion of experimental data
A. D. Ivanova, D. P. Zhurov
Atmospheric Cherenkov telescopes (IACT) of the TAIGA-IACT are part of the TAIGA astrophysical complex located in the Tunka Valley (Republic of Buryatia, Russia), 50 km from Lake Baikal. The complex is a hybrid system of detectors and is being created to solve a wide range of fundamental problems of cosmic ray physics and gamma-ray astronomy. The report presents the result of the mirror alignment of the first TAIGA-IACT using a new, within the framework of the TAIGA-IACT, the Boke method. A criterion for selecting experimental data based on the limiting magnitude parameter is developed and present.
Show AbstractScintillation experiments of the astrophysical complex TAIGA
Scintillation experiments of the astrophysical complex TAIGA
R. D. Monkhoev
Tunka-Grande and TAIGA-Muon scintillation arrays are part of the TAIGA astrophysical complex. This complex is located in the Tunka Valley (Republic of Buryatia, Russia), 50 km from Lake Baikal and is aimed at solving fundamental problems of cosmic ray physics and gamma-ray astronomy. The article provides an overview of the Tunka-Grande and TAIGA-Muon arrays. Main results obtained from the experimental data of the Tunka-Grande array for the first 5 years of its operation are presented. The prospects for studying primary cosmic radiation in the energy range 10^14 - 10^18 eV are discussed.
Show AbstractDevelopment of a charged particle detector based on MCP with CsI photocathode
Development of a charged particle detector based on MCP with CsI photocathode
K. G. Petrukhin$^1$, A. Yu. Barnyakov$^{1,2,3}$, M. Yu. Barnyakov$^{1,2}$, V. E. Blinov$^{1,2,3}$, V. S. Bobrovnikov$^{1,2}$, A. V. Bykov$^{1,2}$, V. Y. Ivanov$^{2,4}$, A. A. Katcin$^{1,2}$, E. V. Mamoshkina$^{1,2}$, I. V. Ovtin$^{1,3}$, S. G. Pivovarov$^{1,2,3}$, V. G. Prisekin$^{1,2}$, E. E. Pyata$^1$
Some future colliding-beam experiments require charged particle detection technology to provide excellent time resolution (better than 50 ps). Charged particle detector with such time resolution is being developed at the Budker Institute of Nuclear Physics (BINP). Prototypes based on microchannel plates with semitransparent CsI-photocathode manufactured at BINP have been tested with a beam of relativistic electrons. The beam test results and calculations are in good agreement. The prototype manufacturing and testing process are presented. Results of CsI-photocathode quantum efficiency measurement end electron test beam results are described.
Show AbstractNew 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 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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