2022, Bogomolov, Y. V., Alekseev, V. V., Levanova, O. A., Mayorov, A. G., Maiorov, A.G., Malakhov, V. V., Богомолов, Юрий Викторович, Алексеев, Владислав Владимирович, Майоров, Андрей Георгиевич, Малахов, Виталий Валерьевич

Unfolding is currently an important stage of processing experimental data, reducing the effect of errors and reconstructing approximately real distributions of quantities. Numerous approaches exist to solve this problem; in particular, they are widely used in the modern physics of atomic nuclei and elementary particles, space physics, and other related areas. However, many algorithms are not designed or are poorly adapted to reconstruct multidimensional distributions corresponding to, e.g., several characteristics of particles measured simultaneously. In this work, a method has been proposed to adapt the singular value decomposition (SVD) unfolding algorithm to the multidimensional case. The proposed modified method has been tested in application to simulation data for the cosmic ray spectrum measured in the PAMELA space experiment. This method not only makes it possible to estimate the real distribution of a multidimensional quantity (momentum and two angles specifying the direction of entering a particle into an instrument) but also provides a better result compared to the classical SVD approach in the one-dimensional case (only the momentum of the p-article). © 2022, Pleiades Publishing, Inc.

2022, Golubkov, V., Khlopov, M., Kirichenko, A., Kravtsova, A., Mayorov, A., Yulbarisov, R., Хлопов, Максим Юрьевич, Майоров, Андрей Георгиевич, Юлбарисов, Рустам Фаритович

Several candidates for antihelium events have been found in the AMS-02 experiment. They cannot be created by natural astrophysical sources and, if confirmed, imply the existence of antimatter stars in our galaxy. This immediately reduces the class of inflationary models with baryosynthesis to those that can provide the creation of an antimatter domain of surviving size together with the general baryon asymmetry of the Universe. To confront the future results of experimental searches for cosmic antihelium with predictions of this hypothesis, we develop numerical studies of the creation and propagation of antihelium flux from antimatter globular clusters in the Galaxy. This article presents the results of such a simulation: a function of the magnetic cut-off for the penetration of antihelium nuclei into the Galaxy disk and an estimate of the energy range in which the search and detection of antihelium is most optimal.

2023, Морозова, Д.Н., Кузнецов, А. В., Майоров, А. Г., Челидзе, К. С., Челидзе, Ксения Сергеевна, Майоров, Андрей Георгиевич, Морозова, Дарья Николаевна

По данным эксперимента PAMELA обнаружены высыпания электронов из радиационного пояса Земли в моменты регистрации гамма-всплесков внеземного происхождения, что порождает гипотезу о взаимосвязи этих явлений. В работе приводятся оценки количества электронов, испытавших взаимодействие с гамма-квантами посредством эффекта Комптона и изменивших свою энергию и траектории в приближении так называемой «игрушечной модели». Получены формула для определения сечения взаимодействия гамма-кванта и покоящегося электрона в зависимости от угла вылета электрона и энергетический спектр вылетевших электронов. В распределении вторичных электронов по энергиям наблюдается узкий пик вблизи максимальной энергии, которая близка к энергии начального гамма-кванта. Проведена оценка верхней границы для вклада рассматриваемого процесса в превышение темпа счета электронов над фоновым значением, зарегистрированных в эксперименте PAMELA. Получено, что предложенный механизм не позволяет объяснить наблюдаемый эффект, рассчитанный темп счета электронов оказывается на несколько порядков ниже, что объясняется малым сечением комптоновского рассеяния

2021, Bikbaev, T. E., Khlopov, M. Yu., Mayorov, A. G., Хлопов, Максим Юрьевич, Майоров, Андрей Георгиевич

The puzzles of direct dark matter searches can be solved in the scenario of dark atoms, which bind hypothetical, stable, lepton-like particles with charge -2n, where n is any natural number, with n nuclei of primordial helium. Avoid experimental discovery because they form with primary helium neutral atom-like states OHe (X – helium), called”dark” atoms. The proposed solution to this problem involves rigorous proof of the existence of a low-energy bound state in the dark atom interaction with nuclei. It implies self-consistent account for nuclear attraction and Coulomb repulsion in such an interaction. We approach the solution of this problem by numerical modeling to reveal the essence of the processes of dark atom interaction with nuclei. We start with the classical three-body problem, to which the effects of quantum physics are added. The numerical model of the dark atom interaction was developed for O- having a charge of -2, bound with He in Bohr-like OHe dark atom and for -2n charged X bound with n α-particle nucleus in the Thomson-like atom XHe. The development of our approach should lead to the solution of the puzzles of direct dark matter searches in the framework of dark atom hypothesis. © 2021 DMFA zaloznistvo. All rights reserved.

2021, Golub, O. A., Mayorov, A. G., Голуб, Ольга Александровна, Майоров, Андрей Георгиевич

© 2021, Allerton Press, Inc.Abstract: Criteria are selected for identifying direct and return albedo protons in the Geant 4 environment by modeling the flight of particles through the PAMELA device. The criteria are applied to PAMELA experimental data. Differential energy spectra of the direct and return albedo protons are reconstructed for low and high geomagnetic latitudes by processing and analyzing the data.

2021, Morozova, D. N., Mayorov, A. G., Морозова, Дарья Николаевна, Майоров, Андрей Георгиевич

© 2021, Pleiades Publishing, Ltd.Abstract: The article studies the relationship between particle precipitation from the Earth’s radiation belt and cosmic gamma-ray bursts. For this purpose, experimental measurements of charged cosmic ray fluxes in the PAMELA experiment and gamma-ray burst observations by the Fermi Observatory are used. Both instruments operated simultaneously in Earth orbit between 2008 and 2016. For the time of each gamma-ray burst detected by the Fermi Observatory during the specified period, the count rate of the PAMELA detectors is analyzed. In order to search for a possible signal from the interaction of a gamma-ray burst with charged particles in the near-Earth space, annual background maps of count rates of the time-of-flight detectors are constructed. The difference between the background count rate and the count rate at the time of the gamma-ray burst arrival (in the time interval several minutes before and after) is analyzed. Several cases are found in which the count rate significantly deviated from the background value at the time of the gamma-ray burst arrival and lasted up to 5–10 min after it.

2020, Bakaldin, A. V., Minaev, P. Y., Suchkov, S. I., Topchiev, N. P., Mikhailova, A. V., Chernysheva, I. V., Galper, A. M., Kheymits, M. D., Leonov, A. A., Mayorov, A. G., Mikhailov, V. V., Yurkin, Y. T., Михайлова, Анна Владимировна, Чернышева, Ирина Вячеславовна, Хеймиц, Максим Дмитриевич, Леонов, Алексей Анатольевич, Майоров, Андрей Георгиевич, Михайлов, Владимир Владимирович, Юркин, Юрий Тихонович

© Published under licence by IOP Publishing Ltd.The future GAMMA-400 γ-ray telescope will provide fundamentally new data on discrete sources and spectra of γ-ray emissions and electrons + positrons due to its unique angular and energy resolutions in the wide energy range from 20 MeV up to several TeV. The γ-ray telescope consists of the anticoincidence system (AC), the converter-Tracker (C), the time-of-flight system (S1 and S2), the position-sensitive and electromagnetic calorimeters (CC1 and CC2), the scintillation detectors of the calorimeter (S3 and S4) and lateral anticoincidence detectors of the calorimeter (LD). To extend the GAMMA-400 capabilities to measure γ-ray bursts, Monte-Carlo simulations were performed for lateral aperture of the one of the versions of GAMMA-400. Second-level trigger based on signals from CC2, LD, S3, and S4 allows us to detect γ-ray bursts in the energy range of ∼10-300 MeV with high effective area about 1 m2.

2021, Adriani, O., Barbarino, G., Bazilevskaya, G. A., Bellotti, R., Mikhailov, V. V., Galper, A. M., Karelin, A. V., Koldashov, S. V., Koldobsky, S. A., Leonov, A. A., Malakhov, V. V., Mayorov, A. G., Spillantini, P., Voronov, S. A., Yurkin, Yu. T., Михайлов, Владимир Владимирович, Колдобский, Сергей Александрович, Леонов, Алексей Анатольевич, Малахов, Виталий Валерьевич, Майоров, Андрей Георгиевич, Воронов, Сергей Александрович, Юркин, Юрий Тихонович

© Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0)The PAMELA magnetic spectrometer, located on board the Resurs-DK1 satellite on Earth polar orbit with altitude of 350-600 km, measured the fluxes of cosmic ray particles and antiparticles in a wide energy range from 50 MeV to several TeVs. In this paper new results on the "all-electron" (sum electrons and positrons) spectrum are presented. New improved analysis on the full data set from 2006 to 2016 allows a significant increase in statistic compared to previously published results and an extension of energy interval up to 1 TeV.

2021, Bruno, A., Martucci, M., Cafagna, F. S., Sparvoli, R., Galper, A. M., Koldashov, S. V., Koldobskiy, S., Leonov, A. A., Malakhov, V. V., Mayorov, A. G., Mikhailov, V. V., Spillantini, P., Voronov, S. A., Yurkin, Y. T., Zharaspayev, T. R., Колдобский, Сергей Александрович, Леонов, Алексей Анатольевич, Малахов, Виталий Валерьевич, Майоров, Андрей Георгиевич, Михайлов, Владимир Владимирович, Воронов, Сергей Александрович, Юркин, Юрий Тихонович

© 2021. The American Astronomical Society. All rights reserved..We present a study of the solar-cycle variations of >80 MeV proton flux intensities in the lower edge of the inner radiation belt, based on the measurements of the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) mission. The analyzed data sample covers an ∼8 yr interval from 2006 July to 2014 September, thus spanning from the decaying phase of the 23rd solar cycle to the maximum of the 24th cycle. We explored the intensity temporal variations as a function of drift shell and proton energy, also providing an explicit investigation of the solar modulation effects at different equatorial pitch angles. PAMELA observations offer new important constraints for the modeling of low-altitude particle radiation environment at the highest trapping energies.

2023, Malakhov, V. V., Golubkov, V. S., Mayorov, A. G., Rodenko, S. A., Yulbarisov, R. F., Малахов, Виталий Валерьевич, Майоров, Андрей Георгиевич, Роденко, Светлана Александровна, Юлбарисов, Рустам Фаритович