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2. Cross Section of the Process \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${e^{+}e^{-}\to n\bar{n}}$$\end{document} near the Threshold

Author

Achasov, M. N., Barnyakov, A. Yu., Bedarev, E. V., Beloborodov, K. I., Berdyugin, A. V., Bogdanchikov, A. G., Botov, A. A., Dimova, T. V., Druzhinin, V. P., Zhabin, V. N., Zharinov, Yu. M., Kardapoltsev, L. V., Kasaev, A. S., Kattsin, A. A., Kovrizhin, D. P., Korol, A. A., Kupich, A. S., Kryukov, A. P., Lysenko, A. P., Melnikova, N. A., Muchnoi, N. Yu., Obrazovsky, A. E., Pakhtusova, E. V., Pugachev, K. V., Rastigeev, S. A., Rogovsky, Yu. A., Senchenko, A. I., Serednyakov, S. I., Silagadze, Z. K., Surin, I. K., Usov, Yu. V., Kharlamov, A. G., Chistyakov, D. E., Shatunov, Yu. M., Sherstyuk, S. P., and Shtol, D. A.

Published
2024
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3. Study of e+e– Annihilation into Hadrons with SND at VEPP-2000

Author

Druzhinin, V. P., Achasov, M. N., Barnyakov, A. Yu., Beloborodov, K. I., Berdyugin, A. V., Bogdanchikov, A. G., Botov, A. A., Dimova, T. V., Kardapoltsev, L. V., Kharlamov, A. G., Korol, A. A., Kovrizhin, D. P., Krukov, A. P., Kupich, A. S., Melnikova, N. A., Obrazovsky, A. E., Pakhtusova, E. V., Pugachev, K. V., Serednyakov, S. I., Shtol, D. A., Silagadze, Z. K., Surin, I. K., Usov, Yu. V., and Zabin, V. N.

Published
2024
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5. Extreme electron–hole drag and negative mobility in the Dirac plasma of graphene

Author

Leonid A. Ponomarenko, Alessandro Principi, Andy D. Niblett, Wendong Wang, Roman V. Gorbachev, Piranavan Kumaravadivel, Alexey I. Berdyugin, Alexey V. Ermakov, Sergey Slizovskiy, Kenji Watanabe, Takashi Taniguchi, Qi Ge, Vladimir I. Fal’ko, Laurence Eaves, Mark T. Greenaway, and Andre K. Geim

Subjects
Science
Abstract

Abstract Coulomb drag between adjacent electron and hole gases has attracted considerable attention, being studied in various two-dimensional systems, including semiconductor and graphene heterostructures. Here we report measurements of electron–hole drag in the Planckian plasma that develops in monolayer graphene in the vicinity of its Dirac point above liquid-nitrogen temperatures. The frequent electron–hole scattering forces minority carriers to move against the applied electric field due to the drag induced by majority carriers. This unidirectional transport of electrons and holes results in nominally negative mobility for the minority carriers. The electron–hole drag is found to be strongest near room temperature, despite being notably affected by phonon scattering. Our findings provide better understanding of the transport properties of charge-neutral graphene, reveal limits on its hydrodynamic description, and also offer insight into quantum-critical systems in general.

Published
2024
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7. One-dimensional proximity superconductivity in the quantum Hall regime

Author

Barrier, Julien, Kim, Minsoo, Kumar, Roshan Krishna, Xin, Na, Kumaravadivel, P., Hague, Lee, Nguyen, E., Berdyugin, A. I., Moulsdale, Christian, Enaldiev, V. V., Prance, J. R., Koppens, F. H. L., Gorbachev, R. V., Watanabe, K., Taniguchi, T., Glazman, L. I., Grigorieva, I. V., Fal’ko, V. I., and Geim, A. K.

Published
2024
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8. Measuring the Neutron Timelike Electromagnetic Form Factor with the SND Detector

Author

Achasov, M. N., Barnyakov, A. Yu., Bedarev, E. V., Beloborodov, K. I., Berdyugin, A. V., Berkaev, D. E., Bogdanchikov, A. G., Botov, A. A., Dimova, T. V., Druzhinin, V. P., Zhabin, V. N., Zharinov, Yu. M., Kardapoltsev, L. V., Kasaev, A. S., Kovrizhin, D. P., Koop, I. A., Korol, A. A., Kupich, A. S., Kryukov, A. P., Lysenko, A. P., Melnikova, N. A., Muchnoi, N. Yu., Obrazovsky, A. E., Pakhtusova, E. V., Pugachev, K. V., Rastigeev, S. A., Rogovsky, Yu. A., Serednyakov, S. I., Silagadze, Z. K., Surin, I. K., Usov, Yu. V., Kharlamov, A. G., Shatunov, Yu. M., and Shtol, D. A.

Published
2023
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9. Study of the Process \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${e^{+}e^{-}\to}{\eta\gamma}{\to 7}\!\gamma$$\end{document} \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sqrt{{s}}{=1.07{-}2}$$\end{document} in the Energy Range \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${e^{+}e^{-}\to}{\eta\gamma}{\to 7}\!\gamma$$\end{document} \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sqrt{{s}}{=1.07{-}2}$$\end{document} GeV

Author

Achasov, M. N., Barnyakov, A. Yu., Beloborodov, K. I., Berdyugin, A. V., Bogdanchikov, A. G., Botov, A. A., Denisov, V. S., Dimova, T. V., Druzhinin, V. P., Fomin, L. B., Kharlamov, A. G., Kardapoltsev, L. V., Kyrpotin, A. N., Koop, I. A., Korol, A. A., Kovrizhin, D. P., Kryukov, A. P., Kupich, A. S., Melnikova, N. A., Muchnoi, N. Yu., Obrazovsky, A. E., Pakhtusova, E. V., Perevedentsev, E. A., Pugachev, K. V., Rogovsky, Yu. A., Serednyakov, S. I., Silagadze, Z. K., Surin, I. K., Timoshenko, M. V., Usov, Yu. V., Zhabin, V. N., Zhulanov, V. V., Zemlyansky, I. M., Shatunov, Yu. M., Shtol, D. A., and Eminov, E. A.

Published
2023
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12. Experimental Study of the \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{e}^{ + }}{{e}^{ - }} \to n\bar {n}$$\end{document} Process at the VEPP-2000 Collider with the SND Detector

Author

Achasov, M. N., Barnyakov, A. Yu., Beloborodov, K. I., Berdyugin, A. V., Bogdanchikov, A. G., Botov, A. A., Dimova, T. V., Druzhinin, V. P., Kardapoltsev, L. V., Kharlamov, A. G., Korol, A. A., Kovrizhin, D. P., Kupich, A. S., Melnikova, N. A., Muchnoy, N. Yu., Obrazovsky, A. E., Pakhtusova, E. V., Pugachev, K. V., Serednyakov, S. I., Shtol, D. A., Silagadze, Z. K., Surin, I. K., Usov, Yu. V., Zhabin, V. N., and Zhulanov, V. V.

Published
2023
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14. Optical Constants and Optical Anisotropy of Ultrathin Gold Films

Author

Diana Akolzina, Vasyl G. Kravets, Alexey I. Berdyugin, and Alexander N. Grigorenko

Subjects
confinement effects, optical anisotropy, optical constants, plasma frequencies, ultrathin gold, Applied optics. Photonics, TA1501-1820, Optics. Light, QC350-467
Abstract

Continuous and homogeneous thin gold films are fabricated on Si–SiO2 substrates using an additional seed layer based on Cu oxide or oxidized Cu. The optical properties of these gold films with thicknesses from 3 to 50 nm are studied with the help of variable angle spectroscopic ellipsometry. The optical constants and the dielectric functions of thin Au films in the wavelength range of 240–1700 nm are extracted by fitting measured ellipsometric data using the Fresnel isotropic and anisotropic models. By applying the Drude approximation to the infrared range, values of the plasma frequency ωp and relaxation time τ are obtained as a function of film thickness. It is found that plasma frequency ωp of the gold films is mostly constant in the thickness range of 3–50 nm with an average being close to the bulk value ωp ≈ 8.45 eV. The relaxation time decreases dramatically from the bulk values of τ ≈ 14 fs to τ ≈ 2 fs for gold films of 3 nm in an agreement with the confinement effect. It is established that the thinnest gold films (≈3 nm) are described better by an anisotropic layer and the underlying reasons for such optical anisotropy are discussed.

Published
2024
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15. Evidence of Jet Activity from the Secondary Black Hole in the OJ 287 Binary System

Author

Mauri J. Valtonen, Staszek Zola, Alok C. Gupta, Shubham Kishore, Achamveedu Gopakumar, Svetlana G. Jorstad, Paul J. Wiita, Minfeng Gu, Kari Nilsson, Alan P. Marscher, Zhongli Zhang, Rene Hudec, Katsura Matsumoto, Marek Drozdz, Waldemar Ogloza, Andrei V. Berdyugin, Daniel E. Reichart, Markus Mugrauer, Lankeswar Dey, Tapio Pursimo, Harry J. Lehto, Stefano Ciprini, T. Nakaoka, M. Uemura, Ryo Imazawa, Michal Zejmo, Vladimir V. Kouprianov, James W. Davidson Jr., Alberto Sadun, Jan Štrobl, Z. R. Weaver, and Martin Jelínek

Subjects
High energy astrophysics, Astrophysics, QB460-466
Abstract

We report the study of a huge optical intraday flare on 2021 November 12 at 2 a.m. UT in the blazar OJ 287. In the binary black hole model, it is associated with an impact of the secondary black hole on the accretion disk of the primary. Our multifrequency observing campaign was set up to search for such a signature of the impact based on a prediction made 8 yr earlier. The first I -band results of the flare have already been reported by Kishore et al. (2024). Here we combine these data with our monitoring in the R -band. There is a big change in the R – I spectral index by 1.0 ± 0.1 between the normal background and the flare, suggesting a new component of radiation. The polarization variation during the rise of the flare suggests the same. The limits on the source size place it most reasonably in the jet of the secondary BH. We then ask why we have not seen this phenomenon before. We show that OJ 287 was never before observed with sufficient sensitivity on the night when the flare should have happened according to the binary model. We also study the probability that this flare is just an oversized example of intraday variability using the Krakow data set of intense monitoring between 2015 and 2023. We find that the occurrence of a flare of this size and rapidity is unlikely. In machine-readable Tables 1 and 2, we give the full orbit-linked historical light curve of OJ 287 as well as the dense monitoring sample of Krakow.

Published
2024
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16. Transport properties of novel Van der Waals materials

Author

Berdyugin, Alexey and Grigorieva, Irina

Subjects
2D materials, 1D states, focusing, electron hydrodynamics, van der Waals heterostructures, TBG, twisted bilayer graphene, graphene, hydrodynamics
Abstract

This work is dedicated to electron transport in novel van der Waals materials. In the first half of this work, I discuss the electron transport properties of graphene encapsulated between two hexagonal boron nitride crystals. Recent studies of this structure revealed that electrons in graphene exhibit a fluid-like behaviour. In this thesis, I extend the studies of graphene electron fluids to include the effect of a magnetic field. We report the violation of the Hall effect due to the presence of the odd/Hall viscosity in such unconventional fluid. Then I turn our attention to graphene superlattices, such as twisted bilayer graphene. Here we show that the properties of this structure are qualitatively different for different twist angles. When the twist angle is relatively high, this system supports micrometre scale ballistic transport, which allowed us to observe the transverse magnetic focusing effect and study the effects of the displacement field in such a system. In a small angle limit, when the twist angle is about 0.1 degree, we found that all the current propagates through the network of one-dimensional channels, which is unique to this type of system.

Published
2020

17. Polarized blazar X-rays imply particle acceleration in shocks

Author

Liodakis, Ioannis, Marscher, Alan P., Agudo, Iván, Berdyugin, Andrei V., Bernardos, Maria I., Bonnoli, Giacomo, Borman, George A., Casadio, Carolina, Casanova, Vı́ctor, Cavazzuti, Elisabetta, Rodriguez Cavero, Nicole, Di Gesu, Laura, Di Lalla, Niccoló, Donnarumma, Immacolata, Ehlert, Steven R., Errando, Manel, Escudero, Juan, Garcı́a-Comas, Maya, Agı́s-González, Beatriz, Husillos, César, Jormanainen, Jenni, Jorstad, Svetlana G., Kagitani, Masato, Kopatskaya, Evgenia N., Kravtsov, Vadim, Krawczynski, Henric, Lindfors, Elina, Larionova, Elena G., Madejski, Grzegorz M., Marin, Frédéric, Marchini, Alessandro, Marshall, Herman L., Morozova, Daria A., Massaro, Francesco, Masiero, Joseph R., Mawet, Dimitri, Middei, Riccardo, Millar-Blanchaer, Maxwell A., Myserlis, Ioannis, Negro, Michela, Nilsson, Kari, O’Dell, Stephen L., Omodei, Nicola, Pacciani, Luigi, Paggi, Alessandro, Panopoulou, Georgia V., Peirson, Abel L., Perri, Matteo, Petrucci, Pierre-Olivier, Poutanen, Juri, Puccetti, Simonetta, Romani, Roger W., Sakanoi, Takeshi, Savchenko, Sergey S., Sota, Alfredo, Tavecchio, Fabrizio, Tinyanont, Samaporn, Vasilyev, Andrey A., Weaver, Zachary R., Zhovtan, Alexey V., Antonelli, Lucio A., Bachetti, Matteo, Baldini, Luca, Baumgartner, Wayne H., Bellazzini, Ronaldo, Bianchi, Stefano, Bongiorno, Stephen D., Bonino, Raffaella, Brez, Alessandro, Bucciantini, Niccoló, Capitanio, Fiamma, Castellano, Simone, Ciprini, Stefano, Costa, Enrico, De Rosa, Alessandra, Del Monte, Ettore, Di Marco, Alessandro, Doroshenko, Victor, Dovčiak, Michal, Enoto, Teruaki, Evangelista, Yuri, Fabiani, Sergio, Ferrazzoli, Riccardo, Garcia, Javier A., Gunji, Shuichi, Hayashida, Kiyoshi, Heyl, Jeremy, Iwakiri, Wataru, Karas, Vladimir, Kitaguchi, Takao, Kolodziejczak, Jeffery J., La Monaca, Fabio, Latronico, Luca, Maldera, Simone, Manfreda, Alberto, Marinucci, Andrea, Matt, Giorgio, Mitsuishi, Ikuyuki, Mizuno, Tsunefumi, Muleri, Fabio, Ng, Stephen C.-Y., Oppedisano, Chiara, Papitto, Alessandro, Pavlov, George G., Pesce-Rollins, Melissa, Pilia, Maura, Possenti, Andrea, Ramsey, Brian D., Rankin, John, Ratheesh, Ajay, Sgró, Carmelo, Slane, Patrick, Soffitta, Paolo, Spandre, Gloria, Tamagawa, Toru, Taverna, Roberto, Tawara, Yuzuru, Tennant, Allyn F., Thomas, Nicolas E., Tombesi, Francesco, Trois, Alessio, Tsygankov, Sergey, Turolla, Roberto, Vink, Jacco, Weisskopf, Martin C., Wu, Kinwah, Xie, Fei, and Zane, Silvia

Published
2022
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19. X-Ray and Multiwavelength Polarization of Mrk 501 from 2022 to 2023

Author

Chien-Ting J. Chen, Ioannis Liodakis, Riccardo Middei, Dawoon E. Kim, Laura Di Gesu, Alessandro Di Marco, Steven R. Ehlert, Manel Errando, Michela Negro, Svetlana G. Jorstad, Alan P. Marscher, Kinwah Wu, Iván Agudo, Juri Poutanen, Tsunefumi Mizuno, Pouya M. Kouch, Elina Lindfors, George A. Borman, Tatiana S. Grishina, Evgenia N. Kopatskaya, Elena G. Larionova, Daria A. Morozova, Sergey S. Savchenko, Ivan S. Troitsky, Yulia V. Troitskaya, Andrey A. Vasilyev, Alexey V. Zhovtan, Francisco José Aceituno, Giacomo Bonnoli, Víctor Casanova, Juan Escudero, Beatriz Agís-González, César Husillos, Jorge Otero Santos, Alfredo Sota, Vilppu Piirola, Ioannis Myserlis, Emmanouil Angelakis, Alexander Kraus, Mark Gurwell, Garrett Keating, Ramprasad Rao, Sincheol Kang, Sang-Sung Lee, Sang-Hyun Kim, Whee Yeon Cheong, Hyeon-Woo Jeong, Chanwoo Song, Andrei V. Berdyugin, Masato Kagitani, Vadim Kravtsov, Anagha P. Nitindala, Takeshi Sakanoi, Ryo Imazawa, Mahito Sasada, Yasushi Fukazawa, Koji S. Kawabata, Makoto Uemura, Tatsuya Nakaoka, Hiroshi Akitaya, Carolina Casadio, Albrecht Sievers, Lucio Angelo Antonelli, Matteo Bachetti, Luca Baldini, Wayne H. Baumgartner, Ronaldo Bellazzini, Stefano Bianchi, Stephen D. Bongiorno, Raffaella Bonino, Alessandro Brez, Niccoló Bucciantini, Fiamma Capitanio, Simone Castellano, Elisabetta Cavazzuti, Stefano Ciprini, Enrico Costa, Alessandra De Rosa, Ettore Del Monte, Niccoló Di Lalla, Immacolata Donnarumma, Victor Doroshenko, Michal Dovčiak, Teruaki Enoto, Yuri Evangelista, Sergio Fabiani, Riccardo Ferrazzoli, Javier A. Garcia, Shuichi Gunji, Kiyoshi Hayashida, Jeremy Heyl, Wataru Iwakiri, Philip Kaaret, Vladimir Karas, Fabian Kislat, Takao Kitaguchi, Jeffery J. Kolodziejczak, Henric Krawczynski, Fabio La Monaca, Luca Latronico, Simone Maldera, Alberto Manfreda, Frédéric Marin, Andrea Marinucci, Herman L. Marshall, Francesco Massaro, Giorgio Matt, Ikuyuki Mitsuishi, Fabio Muleri, C.-Y. Ng, Stephen L. O’Dell, Nicola Omodei, Chiara Oppedisano, Alessandro Papitto, George G. Pavlov, Abel Lawrence Peirson, Matteo Perri, Melissa Pesce-Rollins, Pierre-Olivier Petrucci, Maura Pilia, Andrea Possenti, Simonetta Puccetti, Brian D. Ramsey, John Rankin, Ajay Ratheesh, Oliver J. Roberts, Roger W. Romani, Carmelo Sgró, Patrick Slane, Paolo Soffitta, Gloria Spandre, Douglas A. Swartz, Toru Tamagawa, Fabrizio Tavecchio, Roberto Taverna, Yuzuru Tawara, Allyn F. Tennant, Nicholas E. Thomas, Francesco Tombesi, Alessio Trois, Sergey S. Tsygankov, Roberto Turolla, Jacco Vink, Martin C. Weisskopf, Fei Xie, and Silvia Zane

Subjects
Blazars, Active galaxies, Black holes, Relativistic jets, Spectropolarimetry, Polarimetry, Astrophysics, QB460-466
Abstract

We present multiwavelength polarization measurements of the luminous blazar Mrk 501 over a 14 month period. The 2–8 keV X-ray polarization was measured with the Imaging X-ray Polarimetry Explorer (IXPE) with six 100 ks observations spanning from 2022 March to 2023 April. Each IXPE observation was accompanied by simultaneous X-ray data from NuSTAR, Swift/XRT, and/or XMM-Newton. Complementary optical–infrared polarization measurements were also available in the B , V , R , I , and J bands, as were radio polarization measurements from 4.85 GHz to 225.5 GHz. Among the first five IXPE observations, we did not find significant variability in the X-ray polarization degree and angle with IXPE. However, the most recent sixth observation found an elevated polarization degree at >3 σ above the average of the other five observations. The optical and radio measurements show no apparent correlations with the X-ray polarization properties. Throughout the six IXPE observations, the X-ray polarization degree remained higher than, or similar to, the R -band optical polarization degree, which remained higher than the radio value. This is consistent with the energy-stratified shock scenario proposed to explain the first two IXPE observations, in which the polarized X-ray, optical, and radio emission arises from different regions.

Published
2024
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20. Observations of Low and Intermediate Spectral Peak Blazars with the Imaging X-Ray Polarimetry Explorer

Author

Herman L. Marshall, Ioannis Liodakis, Alan P. Marscher, Niccolò Di Lalla, Svetlana G. Jorstad, Dawoon E. Kim, Riccardo Middei, Michela Negro, Nicola Omodei, Abel L. Peirson, Matteo Perri, Simonetta Puccetti, Marco Laurenti, Iván Agudo, Giacomo Bonnoli, Andrei V. Berdyugin, Elisabetta Cavazzuti, Nicole Rodriguez Cavero, Immacolata Donnarumma, Laura Di Gesu, Jenni Jormanainen, Henric Krawczynski, Elina Lindfors, Greg Madjeski, Frédéric Marin, Francesco Massaro, Luigi Pacciani, Juri Poutanen, Fabrizio Tavecchio, Pouya M. Kouch, Francisco José Aceituno, Maria I. Bernardos, Víctor Casanova, Maya García-Comas, Beatriz Agís-González, César Husillos, Alessandro Marchini, Alfredo Sota, Dmitry Blinov, Ioakeim G. Bourbah, Sebastian Kielhmann, Evangelos Kontopodis, Nikos Mandarakas, Stylianos Romanopoulos, Raphael Skalidis, Anna Vervelaki, George A. Borman, Evgenia N. Kopatskaya, Elena G. Larionova, Daria A. Morozova, Sergey S. Savchenko, Andrey A. Vasilyev, Alexey V. Zhovtan, Carolina Casadio, Juan Escudero, Joana Kramer, Ioannis Myserlis, Efthalia Trainou, Ryo Imazawa, Mahito Sasada, Yasushi Fukazawa, Koji S. Kawabata, Makoto Uemura, Tsunefumi Mizuno, Tatsuya Nakaoka, Hiroshi Akitaya, Joseph R. Masiero, Dimitri Mawet, Georgia V. Panopoulou, Samaporn Tinyanont, Masato Kagitani, Vadim Kravtsov, Takeshi Sakanoi, Matthew Dattolo, Mark Gurwell, Garrett Keating, Ramprasad Rao, Whee Yeon Cheong, Hyeon-Woo Jeong, Sincheol Kang, Sang-Hyun Kim, Sang-Sung Lee, Emmanouil Angelakis, Alexander Kraus, Antonio Hales, Seiji Kameno, Ruediger Kneissl, Hugo Messias, Hiroshi Nagai, Lucio A. Antonelli, Matteo Bachetti, Luca Baldini, Wayne H. Baumgartner, Ronaldo Bellazzini, Stefano Bianchi, Stephen D. Bongiorno, Raffaella Bonino, Alessandro Brez, Niccolò Bucciantini, Fiamma Capitanio, Simone Castellano, Chen-Ting Chen, Stefano Ciprini, Enrico Costa, Alessandra De Rosa, Ettore Del Monte, Alessandro Di Marco, Victor Doroshenko, Michal Dovčiak, Steven R. Ehlert, Teruaki Enoto, Yuri Evangelista, Sergio Fabiani, Riccardo Ferrazzoli, Javier A. Garcia, Shuichi Gunji, Kiyoshi Hayashida, Jeremy Heyl, Wataru Iwakiri, Philip Kaaret, Vladimir Karas, Fabian Kislat, Takao Kitaguchi, Jeffery J. Kolodziejczak, Fabio La Monaca, Luca Latronico, Simone Maldera, Alberto Manfreda, Andrea Marinucci, Giorgio Matt, Ikuyuki Mitsuishi, Fabio Muleri, C.-Y. Ng, Stephen L. O’Dell, Chiara Oppedisano, Alessandro Papitto, George G. Pavlov, Melissa Pesce-Rollins, Pierre-Olivier Petrucci, Maura Pilia, Andrea Possenti, Brian D. Ramsey, John Rankin, Ajay Ratheesh, Oliver J. Roberts, Roger W. Romani, Carmelo Sgrò, Patrick Slane, Paolo Soffitta, Gloria Spandre, Douglas A. Swartz, Toru Tamagawa, Roberto Taverna, Yuzuru Tawara, Allyn F. Tennant, Nicholas E. Thomas, Francesco Tombesi, Alessio Trois, Sergey S. Tsygankov, Roberto Turolla, Jacco Vink, Martin C. Weisskopf, Kinwah Wu, Fei Xie, and Silvia Zane

Subjects
X-ray astronomy, Polarimetry, Spectropolarimetry, Radio loud quasars, X-ray quasars, Blazars, Astrophysics, QB460-466
Abstract

We present X-ray polarimetry observations from the Imaging X-ray Polarimetry Explorer (IXPE) of three low spectral peak and one intermediate spectral peak blazars, namely 3C 273, 3C 279, 3C 454.3, and S5 0716+714. For none of these objects was IXPE able to detect X-ray polarization at the 3 σ level. However, we placed upper limits on the polarization degree at ∼10%–30%. The undetected polarizations favor models where the X-ray band is dominated by unpolarized photons upscattered by relativistic electrons in the jets of blazars, although hadronic models are not completely eliminated. We discuss the X-ray polarization upper limits in the context of our contemporaneous multiwavelength polarization campaigns.

Published
2024
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21. Experimental study of the $$e^+e^-\rightarrow n{\bar{n}}$$ e + e - → n n ¯ process at the VEPP-2000 $$e^+e^-$$ e + e - collider with the SND detector

Author

SND Collaboration, M. N. Achasov, A. Yu. Barnyakov, K. I. Beloborodov, A. V. Berdyugin, D. E. Berkaev, A. G. Bogdanchikov, A. A. Botov, G. S. Chizhik, T. V. Dimova, V. P. Druzhinin, L. V. Kardapoltsev, A. G. Kharlamov, V. A. Kladov, I. A. Koop, A. A. Korol, D. P. Kovrizhin, A. S. Kupich, A. P. Lysenko, N. A. Melnikova, N. Yu. Muchnoi, A. E. Obrazovsky, E. V. Pakhtusova, E. A. Perevedentsev, K. V. Pugachev, S. I. Serednyakov, Z. K. Silagadze, P. Yu. Shatunov, Yu. M. Shatunov, D. A. Shtol, D. B. Shwartz, I. K. Surin, Yu. V. Usov, I. M. Zemlyansky, V. N. Zhabin, and V. V. Zhulanov

Subjects
Astrophysics, QB460-466, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract The process $$e^+e^-\rightarrow n{\bar{n}}$$ e + e - → n n ¯ is studied in the experiment at the VEPP-2000 $$e^+e^-$$ e + e - collider with the SND detector. The technique of the time measurements in the multichannel NaI(Tl) electromagnetic calorimeter is used to select $$n{\bar{n}}$$ n n ¯ events. The value of the measured cross section in the center-of-mass energy range from 1.894 to 2 GeV varies from 0.5 to 0.35 nb. The effective neutron timelike form factor is derived from the measured cross section and compared with the proton form factor. The ratio of the neutron electric and magnetic form factors is obtained from the analysis of the antineutron polar angle distribution and found to be consistent with unity.

Published
2022
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22. Overview of Recent Results from the SND Experiment at the VEPP-2000 Collider

Author

Beloborodov, K. I., Achasov, M. N., Barnyakov, A. Yu., Berdyugin, A. V., Bogdanchikov, A. G., Botov, A. A., Dimova, T. V., Druzhinin, V. P., Kardapoltsev, L. V., Kharlamov, A. G., Korol, A. A., Kovrizhin, D. P., Kupich, A. S., Melnikova, N. A., Obrazovsky, A. E., Pakhtusova, E. V., Pugachev, K. V., Serednyakov, S. I., Shtol, D. A., Silagadze, Z. K., Surin, I. K., Usov, Yu. V., and Zabin, V. N.

Published
2022
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23. Measurement of the Neutron Timelike Electromagnetic form Factors at the VEPP-2000 e+e– Collider with the SND Detector

Author

Achasov, M. N., Barnyakov, A. Yu., Baykov, A. A., Beloborodov, K. I., Berdyugin, A. V., Bogdanchikov, A. G., Botov, A. A., Dimova, T. V., Druzhinin, V. P., Golubev, V. B., Kardapoltsev, L. V., Kharlamov, A. G., Korol, A. A., Kovrizhin, D. P., Kupich, A. S., Martin, K. A., Melnikova, N. A., Muchnoy, N. Yu., Obrazovsky, A. E., Pakhtusova, E. V., Pugachev, K. V., Savchenko, Ya. S., Serednyakov, S. I., Shtol, D. A., Silagadze, Z. K., Surin, I. K., Usov, Yu. V., Zhabin, V. N., and Zhulanov, V. V.

Published
2022
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24. Studying geometry of the ultraluminous X-ray pulsar Swift J0243.6+6124 using X-ray and optical polarimetry.

Author

Poutanen, Juri, Tsygankov, Sergey S., Doroshenko, Victor, Forsblom, Sofia V., Jenke, Peter, Kaaret, Philip, Berdyugin, Andrei V., Blinov, Dmitry, Kravtsov, Vadim, Liodakis, Ioannis, Tzouvanou, Anastasia, Di Marco, Alessandro, Heyl, Jeremy, La Monaca, Fabio, Mushtukov, Alexander A., Pavlov, George G., Salganik, Alexander, Veledina, Alexandra, Weisskopf, Martin C., and Zane, Silvia

Subjects
ANGULAR momentum (Mechanics), NEUTRON stars, EDDINGTON mass limit, OPTICAL measurements, BREWSTER'S angle
Abstract

Discovery of pulsations from a number of ultra-luminous X-ray (ULX) sources proved that accretion onto neutron stars can produce luminosities exceeding the Eddington limit by several orders of magnitude. The conditions necessary to achieve such high luminosities as well as the exact geometry of the accretion flow in the neutron star vicinity are, however, a matter of debate. The pulse phase-resolved polarization measurements that became possible with the launch of the Imaging X-ray Polarimetry Explorer (IXPE) can be used to determine the pulsar geometry and its orientation relative to the orbital plane. They provide an avenue to test different theoretical models of ULX pulsars. In this paper we present the results of three IXPE observations of the first Galactic ULX pulsar Swift J0243.6+6124 during its 2023 outburst. We find strong variations in the polarization characteristics with the pulsar phase. The average polarization degree increases from about 5% to 15% as the flux dropped by a factor of three in the course of the outburst. The polarization angle (PA) as a function of the pulsar phase shows two peaks in the first two observations, but changes to a characteristic sawtooth pattern in the remaining data set. This is not consistent with a simple rotating vector model. Assuming the existence of an additional constant polarized component, we were able to fit the three observations with a common rotating vector model and obtain constraints on the pulsar geometry. In particular, we find the pulsar angular momentum inclination with respect to the line of sight of ip = 15°–40°, the magnetic obliquity of θp = 60°–80°, and the pulsar spin position angle of χp ≈ −50°, which significantly differs from the constant component PA of about 10°. Combining these X-ray measurements with the optical PA, we find evidence for at least a 30° misalignment between the pulsar angular momentum and the binary orbital axis. [ABSTRACT FROM AUTHOR]

Published
2024
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25. Cross Section of the Process near the Threshold.

Author

Achasov, M. N., Barnyakov, A. Yu., Bedarev, E. V., Beloborodov, K. I., Berdyugin, A. V., Bogdanchikov, A. G., Botov, A. A., Dimova, T. V., Druzhinin, V. P., Zhabin, V. N., Zharinov, Yu. M., Kardapoltsev, L. V., Kasaev, A. S., Kattsin, A. A., Kovrizhin, D. P., Korol, A. A., Kupich, A. S., Kryukov, A. P., Lysenko, A. P., and Melnikova, N. A.

Subjects
CENTER of mass, TIME measurements, COLLIDERS (Nuclear physics), THRESHOLD energy, NEUTRONS
Abstract

The cross section was measured at center of mass (c.m.) energies from the threshold to 1908 MeV. The experiment to measure the cross section has been carried out at the VEPP-2000 collider in 13 energy points. The SND detector is used to detect the produced neutron–antineutrons () events. A special time measurement system on the calorimeter was used to select the time-delayed events. The measured cross section is 0.4–0.6 nb. The neutron effective timelike form factor in the energy range under study varies from 0.3 to 0.6. [ABSTRACT FROM AUTHOR]

Published
2024
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26. Study of the process $$e^+e^- \rightarrow \eta \eta \gamma $$ e + e - → η η γ in the energy range $$\sqrt{s} = \text{1.17--2.00 }$$ s = 1.17--2.00 GeV with the SND detector

Author

M. N. Achasov, A. Yu. Barnyakov, K. I. Beloborodov, A. V. Berdyugin, D. E. Berkaev, A. G. Bogdanchikov, A. A. Botov, T. V. Dimova, V. P. Druzhinin, A. N. Kirpotin, L. V. Kardapoltsev, A. S. Kasaev, A. G. Kharlamov, I. A. Koop, A. A. Korol, D. P. Kovrizhin, A. S. Kupich, K. A. Martin, N. A. Melnikova, N. Yu. Muchnoy, A. E. Obrazovsky, E. V. Pakhtusova, K. V. Pugachev, D. V. Rabusov, Yu. A. Rogovsky, A. I. Senchenko, S. I. Serednyakov, D. N. Shatilov, Yu. M. Shatunov, D. A. Shtol, D. B. Shwartz, Z. K. Silagadze, I. K. Surin, M. V. Timoshenko, Yu. V. Usov, V. N. Zhabin, V. V. Zhulanov, and SND Collaboration

Subjects
Astrophysics, QB460-466, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract The process $$e^+e^-\rightarrow \eta \eta \gamma $$ e + e - → η η γ is studied in the center-of-mass energy range 1.17–2.00 GeV using data with an integrated luminosity of 201 pb $$^{-1}$$ - 1 collected by the SND detector at the VEPP-2000 $$e^+e^-$$ e + e - collider. The $$e^+e^-\rightarrow \eta \eta \gamma $$ e + e - → η η γ cross section is measured for the first time. It is shown that the dominant mechanism of this reaction is the transition through the $$\phi \eta $$ ϕ η intermediate state. Our result on the $$e^+e^-\rightarrow \eta \eta \gamma $$ e + e - → η η γ cross section is consistent with the $$e^+e^-\rightarrow \phi \eta $$ e + e - → ϕ η measurement in the $$\phi \rightarrow K^+ K^-$$ ϕ → K + K - mode. The search for radiative processes contributing to the $$e^+e^-\rightarrow \eta \eta \gamma $$ e + e - → η η γ cross section is performed, and no significant signal is observed.

Published
2022
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27. UV spectropolarimetry with Polstar: protoplanetary disks

Author

Wisniewski, John P., Berdyugin, Andrei V., Berdyugina, Svetlana V., Danchi, William C., Dong, Ruobing, Oudmaijer, René D., Airapetian, Vladimir S., Brittain, Sean D., Gayley, Ken, Ignace, Richard, Langlois, Maud, Lawson, Kellen D., Lomax, Jamie R., Rich, Evan A., Tamura, Motohide, Vink, Jorick S., and Scowen, Paul A.

Published
2022
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28. Graphene’s non-equilibrium fermions reveal Doppler-shifted magnetophonon resonances accompanied by Mach supersonic and Landau velocity effects

Author

M. T. Greenaway, P. Kumaravadivel, J. Wengraf, L. A. Ponomarenko, A. I. Berdyugin, J. Li, J. H. Edgar, R. Krishna Kumar, A. K. Geim, and L. Eaves

Subjects
Science
Abstract

Magneto-oscillations have revealed many interesting phenomena in graphene and quantum Hall systems, but they are typically measured at low currents and in equilibrium. Here, the authors report several non-equilibrium quantum effects observed in magneto-oscillations in graphene at high currents.

Published
2021
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29. Observational Implications of OJ 287’s Predicted 2022 Disk Impact in the Black Hole Binary Model

Author

Mauri J. Valtonen, Lankeswar Dey, Achamveedu Gopakumar, Staszek Zola, Anne Lähteenmäki, Merja Tornikoski, Alok C. Gupta, Tapio Pursimo, Emil Knudstrup, Jose L. Gomez, Rene Hudec, Martin Jelínek, Jan Štrobl, Andrei V. Berdyugin, Stefano Ciprini, Daniel E. Reichart, Vladimir V. Kouprianov, Katsura Matsumoto, Marek Drozdz, Markus Mugrauer, Alberto Sadun, Michal Zejmo, Aimo Sillanpää, Harry J. Lehto, Kari Nilsson, Ryo Imazawa, and Makoto Uemura

Subjects
BL Lacertae objects: individual: OJ 287, quasars: supermassive black holes, accretion, accretion discs, gravitational waves, galaxies: jets, Astronomy, QB1-991
Abstract

We present a summary of the results of the OJ 287 observational campaign, which was carried out during the 2021/2022 observational season. This season is special in the binary model because the major axis of the precessing binary happens to lie almost exactly in the plane of the accretion disc of the primary. This leads to pairs of almost identical impacts between the secondary black hole and the accretion disk in 2005 and 2022. In 2005, a special flare called “blue flash” was observed 35 days after the disk impact, which should have also been verifiable in 2022. We did observe a similar flash and were able to obtain more details of its properties. We describe this in the framework of expanding cloud models. In addition, we were able to identify the flare arising exactly at the time of the disc crossing from its photo-polarimetric and gamma-ray properties. This is an important identification, as it directly confirms the orbit model. Moreover, we saw a huge flare that lasted only one day. We may understand this as the lighting up of the jet of the secondary black hole when its Roche lobe is suddenly flooded by the gas from the primary disk. Therefore, this may be the first time we directly observed the secondary black hole in the OJ 287 binary system.

Published
2023
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30. Photocatalysts Based on Graphite-like Carbon Nitride with a Low Content of Rhodium and Palladium for Hydrogen Production under Visible Light

Author

Angelina V. Zhurenok, Danila B. Vasichenko, Semen N. Berdyugin, Evgeny Yu. Gerasimov, Andrey A. Saraev, Svetlana V. Cherepanova, and Ekaterina A. Kozlova

Subjects
photocatalysis, hydrogen evolution, g-C3N4, noble metals, rhodium, palladium, Chemistry, QD1-999
Abstract

In this study, we proposed photocatalysts based on graphite-like carbon nitride with a low content (0.01–0.5 wt.%) of noble metals (Pd, Rh) for hydrogen evolution under visible light irradiation. As precursors of rhodium and palladium, labile aqua and nitrato complexes [Rh2(H2O)8(μ-OH)2](NO3)4∙4H2O and (Et4N)2[Pd(NO3)4], respectively, were proposed. To obtain metallic particles, reduction was carried out in H2 at 400 °C. The synthesized photocatalysts were studied using X-ray diffraction, X-ray photoelectron spectroscopy, UV–Vis diffuse reflectance spectroscopy and high-resolution transmission electron microscopy. The activity of the photocatalysts was tested in the hydrogen evolution from aqueous and aqueous alkaline solutions of TEOA under visible light with a wavelength of 428 nm. It was shown that the activity for the 0.01–0.5% Rh/g-C3N4 series is higher than in the case of the 0.01–0.5% Pd/g-C3N4 photocatalysts. The 0.5% Rh/g-C3N4 sample showed the highest activity per gram of catalyst, equal to 3.9 mmol gcat–1 h–1, whereas the most efficient use of the metal particles was found over the 0.1% Rh/g-C3N4 photocatalyst, with the activity of 2.4 mol per gram of Rh per hour. The data obtained are of interest and can serve for further research in the field of photocatalytic hydrogen evolution using noble metals as cocatalysts.

Published
2023
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31. Experimental study of the e+e-→nn¯e+e- process at the VEPP-2000 e+e-→nn¯e+e- collider with the SND detector

Author

Achasov, M. N., Barnyakov, A. Yu., Beloborodov, K. I., Berdyugin, A. V., Berkaev, D. E., Bogdanchikov, A. G., Botov, A. A., Chizhik, G. S., Dimova, T. V., Druzhinin, V. P., Kardapoltsev, L. V., Kharlamov, A. G., Kladov, V. A., Koop, I. A., Korol, A. A., Kovrizhin, D. P., Kupich, A. S., Lysenko, A. P., Melnikova, N. A., Muchnoi, N. Yu., Obrazovsky, A. E., Pakhtusova, E. V., Perevedentsev, E. A., Pugachev, K. V., Serednyakov, S. I., Silagadze, Z. K., Shatunov, P. Yu., Shatunov, Yu. M., Shtol, D. A., Shwartz, D. B., Surin, I. K., Usov, Yu. V., Zemlyansky, I. M., Zhabin, V. N., and Zhulanov, V. V.

Published
2022
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32. UV Spectropolarimetry With Polstar: Protoplanetary Disks

Author

John P Wisniewski, Andrei V Berdyugin, Svetlana V Berdyugina, William C Danchi, Ruobing Dong, René D Oudmaijer, Vladimir Airapetian, Sean D Brittain, Ken Gayley, Richard Ignace, Maude Langlois, Kellen D Lawson, Jamie R Lomax, Evan A Rich, Motohide Tamura, Jorick S Vink, and Paul A Scowen

Subjects
Instrumentation and Photography, Astronomy
Abstract

Polstar is a proposed NASA MIDEX mission that carries a high resolution UV spectropolarimeter capable of measure all four Stokes parameters onboard a 60 cm telescope. The mission has been designed to pioneer the field of time-domain UV spectropolarimetry. Time domain UV spectropolarimetry offers the best resource to determine the geometry and physical conditions of protoplanetary disks from the stellar surface to <5 AU.We detail two key objectives that a dedicated time domain UV spectropolarimetry survey, such as that enabled by Polstar or a similar mission concept, could achieve: 1) Test the hypothesis that magneto-accretion operating in young planet-forming disks around lower-mass stars transitions to boundary layer accretion in planet-forming disks around higher mass stars; and 2) Discriminate whether transient events in the innermost regions of planet-forming disks of intermediate mass stars are caused by inner disk misalignments or from stellar or disk emissions.

Published
2022
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33. Polarized Blazar X-Rays Imply Particle Acceleration in Shocks

Author

Ioannis Liodakis, Alan P. Marscher, Iván Agudo, Andrei V. Berdyugin, Maria I. Bernardos, Giacomo Bonnoli, George A. Borman, Carolina Casadio, Víctor Casanova, Elisabetta Cavazzuti, Nicole R. Cavero, Laura Di Gesu, Niccoló Di Lalla, Immacolata Donnarumma, Steven R. Ehlert, Manel Errando, Juan Escudero, Maya García-Comas, Beatriz Agís-González, César Husillos, Jenni Jormanainen, Svetlana G. Jorstad, Masato Kagitani, Evgenia N. Kopatskaya, Vadim Kravtsov, Henric Krawczynski, Elina Lindfors, Elena G. Larionova, Grzegorz M. Madejski, Frédéric Marin, Alessandro Marchini, Herman L. Marshall, Daria A. Morozova, Francesco Massaro, Joseph R. Masiero, Stephen L. O'Dell, Wayne H. Baumgartner, Stephen D. Bongiorno, Jeffery J. Kolodziejczak, Brian D. Ramsey, Allyn F. Tennant, Nicolas E. Thomas, and Martin C. Weisskopf

Subjects
Astrophysics
Abstract

Most of the light from blazars, active galactic nuclei with jets of magnetized plasma that point nearly along the line of sight, is produced by high-energy particles, up to around 1 TeV. Although the jets are known to be ultimately powered by a supermassive black hole, how the particles are accelerated to such high energies has been an unanswered question. The process must be related to the magnetic field, which can be probed by observations of the polarization of light from the jets. Measurements of the radio to optical polarization—the only range available until now—probe extended regions of the jet containing particles that left the acceleration site days to years earlier, and hence do not directly explore the acceleration mechanism, as could X-ray measurements. Here we report the detection of X-ray polarization from the blazar Markarian 501 (Mrk 501). We measure an X-ray linear polarization degree Π_X of around 10%, which is a factor of around 2 higher than the value at optical wavelengths, with a polarization angle parallel to the radio jet. This points to a shock front as the source of particle acceleration and also implies that the plasma becomes increasingly turbulent with distance from the shock.

Published
2022
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34. Searching for magnetic fields in featureless white dwarfs with the DIPOL-UF polarimeter at the Nordic Optical Telescope.

Author

Berdyugin, A., Landstreet, J. D., Bagnulo, S., Piirola, V., and Berdyugina, S. V.

Subjects
*STELLAR magnetic fields, *OPTICAL telescopes, *MAGNETIC flux density, *OPTICAL spectra, *SPECTRAL lines
Abstract

About 20% of the white dwarfs possess a magnetic field that may be detected by the splitting and/or polarization of their spectral lines. As they cool, the effective temperatures of the white dwarfs become so low that no spectral lines can be seen in the visible wavelength range. If their atmospheres are not polluted by the debris of a planetary system, these cool white dwarfs have featureless optical spectra. Until quite recently, very little was known about the incidence of magnetic fields in these objects. However, when observed with polarimetric techniques, a significant number of featureless white dwarfs reveal strong magnetic fields in their optical continuum spectra. Measuring the occurrence rate and strength of magnetic fields in old white dwarfs may help us to understand how these fields are generated and evolve. We report the results of an ongoing survey of cool white dwarfs with the high-precision broad-band polarimeter DIPOL-UF, which is deployed at the Nordic Optical Telescope on La Palma, Spain. This survey has led to the firm discovery of 13 new cool magnetic white dwarfs in the solar neighborhood so far, including six new detections that we report in this paper. [ABSTRACT FROM AUTHOR]

Published
2024
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36. Measurement of the e + e − → π + π − process cross section with the SND detector at the VEPP-2000 collider in the energy region 0.525 < s $$ \sqrt{s} $$ < 0.883 GeV

Author

SND collaboration, M. N. Achasov, A. A. Baykov, A. Yu. Barnyakov, K. I. Beloborodov, A. V. Berdyugin, D. E. Berkaev, A. G. Bogdanchikov, A. A. Botov, T. V. Dimova, V. P. Druzhinin, V. B. Golubev, L. V. Kardapoltsev, A. G. Kharlamov, I. A. Koop, A. A. Korol, D. P. Kovrizhin, A. S. Kupich, A. P. Lysenko, K. A. Martin, N. A. Melnikova, N. Yu. Muchnoi, A. E. Obrazovsky, E. V. Pakhtusova, E. A. Perevedentsev, K. V. Pugachev, Y. S. Savchenko, S. I. Serednyakov, Z. K. Silagadze, P. Yu. Shatunov, Yu. M. Shatunov, D. A. Shtol, D. B. Shwartz, I. K. Surin, Yu. V. Usov, I. M. Zemlyansky, and V. N. Zhabin

Subjects
e +-e − Experiments, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract The cross section of the process e + e − → π + π − has been measured in the Spherical Neutral Detector (SND) experiment at the VEPP-2000 e + e − collider VEPP-2000 in the energy region 525 < s $$ \sqrt{s} $$ < 883 MeV. The measurement is based on data with an integrated luminosity of about 4.6 pb −1. The systematic uncertainty of the cross section determination is 0.8% at s $$ \sqrt{s} $$ > 0.600 GeV. The ρ meson parameters are obtained as m ρ = 775.3 ± 0.5 ± 0.6 MeV, Γ ρ = 145.6 ± 0.6 ± 0.8 MeV, B ρ→e+e− × B ρ→π+π− = (4.89 ± 0.02 ± 0.04) × 10 −5, and the parameters of the e + e − → ω → π + π − process, suppressed by G-parity, as B ω→e+e− × B ω→π+π− = (1.32 ± 0.06 ± 0.02) × 10 −6 and and ϕ ρω = 110.7 ± 1.5 ± 1.0 degrees.

Published
2021
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37. Reengineering of business processes of a commercial bank in the information space

Author

Alexander A. Berdyugin

Subjects
reengineering of business processes, electronic banking technologies, the risk of cyberattacks, information security, high-speed printing method., Information technology, T58.5-58.64, Information theory, Q350-390
Abstract

The need in this research arises since issues of labor reorganization in a financial institution has not been elaborated and studied scientifically and practically, considering development of technology and cybercrime. The article deals with reorganization of labor in a credit and financial institution. The object of research is the operations of a credit institution. The subject is reengineering of business processes of a Bank, which is an alternative to the “Six Sigma” and “Kaizen” methods. The purpose of these methods is to improve the quality of business processes of a commercial bank minimizing the number of operational errors. The review of sources made it possible to determine the requirements for ensuring cybersecurity and increasing customer confidence in electronic banking technologies. Development dynamics of the countries of the world according to their readiness of transition to e-government, depending on the value of the gross national product per capita, is analyzed. As a key performance indicator of the company, an assessment method has been developed for calculate the amount of fine for cybercriminals. An example of a quantitative assessment of the penalty is given. The studied reengineering of the business process of a commercial bank is aimed at improving the process of work of the client and the bank employee at the computer. The necessity of introducing the method of high-speed typing (a topic related to cybersecurity) in the educational program of Russia is investigated and justified. The research results may be of further use for the development of risk management in credit institutions using electronic banking technologies.

Published
2021
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38. Study of the Process \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${e}^{{+}}{e}^{{-}}{\to}{\eta\pi}^{{0}}{\gamma}$$\end{document} \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sqrt{{s}}{=}{1.05{-}2.00}$$\end{document} in the Cossision-Energy Range of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${e}^{{+}}{e}^{{-}}{\to}{\eta\pi}^{{0}}{\gamma}$$\end{document} \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sqrt{{s}}{=}{1.05{-}2.00}$$\end{document} GeV

Author

Achasov, M. N., Barnyakov, A. Yu., Baykov, A. A., Beloborodov, K. I., Berdyugin, A. V., Bogdanchikov, A. G., Botov, A. A., Golubev, V. B., Dimova, T. V., Druzhinin, V. P., Zhabin, V. N., Kardapoltsev, L. V., Kovrizhin, D. P., Korol, A. A., Kupich, A. S., Martin, K. A., Melnikova, N. A., Muchnoi, N. Yu., Obrazovsky, A. E., Pakhtusova, E. V., Pugachev, K. V., Savchenko, Ya. S., Serednyakov, S. I., Silagadze, Z. K., Surin, I. K., Usov, Yu. V., Kharlamov, A. G., and Shtol, D. A.

Published
2021
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39. Study of the Form Factor \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\gamma {\text{*}}\omega {{\pi }^{0}}$$\end{document} Using the SND Detector

Author

Achasov, M. N., Baikov, A. A., Barnyakov, A. Yu., Beloborodov, K. I., Berdyugin, A. V., Bogdanchikov, A. G., Botov, A. A., Golubev, V. B., Dimova, T. V., Druzhinin, V. P., Zhabin, V. N., Zhulanov, V. V., Kardapoltsev, L. V., Kovrizhin, D. P., Korol’, A. A., Kupich, A. S., Martin, K. A., Mel’nikova, N. A., Muchnoi, N. Yu., Obrazovskii, A. E., Pakhtusova, E. V., Pugachev, K. V., Savchenko, Ya. S., Serednyakov, S. I., Silagadze, Z. K., Surin, I. K., Usov, Yu. V., Kharlamov, A. G., and Shtol’, D. A.

Published
2021
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40. Measurement of the Cross Section for the Process \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${e^{+}e^{-}}{\to}{\omega\pi}^{{0}}{\to}{\pi}^{{+}}{\pi}^{{-}}{\pi}^{{0}}{\pi}^{{0}}$$\end{document} with the SND Detector

Author

Achasov, M. N., Barnyakov, A. Yu., Baykov, A. A., Beloborodov, K. I., Berdyugin, A. V., Bogdanchikov, A. G., Botov, A. A., Golubev, V. B., Dimova, T. V., Druzhinin, V. P., Zhabin, V. N., Zhulanov, V. V., Kardapoltsev, L. V., Kovrizhin, D. P., Korol, A. A., Kupich, A. S., Martin, K. A., Melnikova, N. A., Muchnoi, N. Yu., Obrazovsky, A. E., Pakhtusova, E. V., Pugachev, K. V., Savchenko, Ya. S., Serednyakov, S. I., Silagadze, Z. K., Surin, I. K., Usov, Yu. V., Kharlamov, A. G., and Shtol, D. A.

Published
2021
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41. Measurement of the Cross Section for the Process \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${e^{+}e^{-}}{\to}{K}^{{+}}{K}^{{-}}{\pi}^{{0}}$$\end{document} \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sqrt{{s}}{=}{1.3{-}2.0}$$\end{document} with the SND Detector at Collision Energies of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${e^{+}e^{-}}{\to}{K}^{{+}}{K}^{{-}}{\pi}^{{0}}$$\end{document} \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sqrt{{s}}{=}{1.3{-}2.0}$$\end{document} GeV in the Center-of-Mass Frame

Author

Achasov, M. N., Barnyakov, A. Yu., Barnyakov, M. Yu., Beloborodov, K. I., Berdyugin, A. V., Bogdanchikov, A. G., Botov, A. A., Buzykaev, A. R., Golubev, V. B., Dimova, T. V., Druzhinin, V. P., Kardapoltsev, L. V., Kovrizhin, D. P., Korol, A. A., Kravchenko, E. A., Kupich, A. S., Martin, K. A., Melnikova, N. A., Obrazovsky, A. E., Onuchin, A. P., Pakhtusova, E. V., Pugachev, K. V., Serednyakov, S. I., Silagadze, Z. K., Surin, I. K., Usov, Yu. V., Kharlamov, A. G., and Shtol, D. A.

Published
2021
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42. Measurement of the $$e^+e^- \rightarrow K^+ K^- \pi ^0$$ e + e - → K + K - π 0 cross section with the SND detector

Author

M. N. Achasov, A. Yu. Barnyakov, M. Yu. Barnyakov, A. A. Baykov, K. I. Beloborodov, A. V. Berdyugin, D. E. Berkaev, A. G. Bogdanchikov, A. A. Botov, A. R. Buzykaev, T. V. Dimova, V. P. Druzhinin, V. B. Golubev, L. V. Kardapoltsev, A. G. Kharlamov, A. A. Korol, D. P. Kovrizhin, E. A. Kravchenko, A. S. Kupich, A. P. Lysenko, K. A. Martin, N. Yu. Muchnoy, N. A. Melnikova, A. E. Obrazovsky, A. P. Onuchin, E. V. Pakhtusova, E. A. Perevedentsev, K. V. Pugachev, Y. S. Savchenko, S. I. Serednyakov, P. Yu. Shatunov, Yu. M. Shatunov, D. A. Shtol, D. B. Shwartz, Z. K. Silagadze, I. K. Surin, Yu. A. Tikhonov, Yu. V. Usov, I. M. Zemlyansky, V. N. Zhabin, and V. V. Zhulanov

Subjects
Astrophysics, QB460-466, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract The process $$e^+e^-\rightarrow K^+K^-\pi ^0$$ e + e - → K + K - π 0 is studied with the SND detector at the VEPP-2000 $$e^+e^-$$ e + e - collider. Basing on data with an integrated luminosity of 26.4 $$\hbox {pb}^{-1}$$ pb - 1 we measure the $$e^+e^-\rightarrow K^+K^-\pi ^0$$ e + e - → K + K - π 0 cross section in the center-of-mass energy range from 1.28 up to 2 GeV. The measured mass spectrum of the $$K\pi $$ K π system indicates that the dominant mechanism of this reaction is the transition through the $$K^{*}(892)K$$ K ∗ ( 892 ) K intermediate state. The cross section for the $$\phi \pi ^0$$ ϕ π 0 intermediate state is measured separately. The SND results are consistent with previous measurements in the BABAR experiment and have comparable accuracy. We study the effect of the interference between the $$\phi \pi ^0$$ ϕ π 0 and $$K^*K$$ K ∗ K amplitudes. It is found that the interference gives sizable contribution to the measured $$e^+e^- \rightarrow \phi \pi ^0\rightarrow K^+K^-\pi ^0$$ e + e - → ϕ π 0 → K + K - π 0 cross section below 1.7 GeV.

Published
2020
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43. Long-range ballistic transport of Brown-Zak fermions in graphene superlattices

Author

Julien Barrier, Piranavan Kumaravadivel, Roshan Krishna Kumar, L. A. Ponomarenko, Na Xin, Matthew Holwill, Ciaran Mullan, Minsoo Kim, R. V. Gorbachev, M. D. Thompson, J. R. Prance, T. Taniguchi, K. Watanabe, I. V. Grigorieva, K. S. Novoselov, A. Mishchenko, V. I. Fal’ko, A. K. Geim, and A. I. Berdyugin

Subjects
Science
Abstract

Here, the authors show that Brown-Zak fermions in graphene-on-boron-nitride superlattices exhibit mobilities above 106 cm2/V s and micrometer scale ballistic transport.

Published
2020
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44. Study of the process $$e^+e^- \rightarrow \eta \pi ^0\gamma $$ e + e - → η π 0 γ in the energy range $$\sqrt{s} = {1.05-2.00}$$ s = 1.05 - 2.00 GeV with the SND detector

Author

M. N. Achasov, A. Yu. Barnyakov, A. A. Baykov, K. I. Beloborodov, A. V. Berdyugin, D. E. Berkaev, A. G. Bogdanchikov, A. A. Botov, T. V. Dimova, V. P. Druzhinin, V. B. Golubev, A. N. Kirpotin, L. V. Kardapoltsev, A. S. Kasaev, A. G. Kharlamov, I. A. Koop, A. A. Korol, D. P. Kovrizhin, A. S. Kupich, K. A. Martin, N. A. Melnikova, N. Yu. Muchnoy, A. E. Obrazovsky, E. V. Pakhtusova, K. V. Pugachev, D. V. Rabusov, Yu. A. Rogovsky, Y. S. Savchenko, A. I. Senchenko, S. I. Serednyakov, D. N. Shatilov, Yu. M. Shatunov, D. A. Shtol, D. B. Shwartz, Z. K. Silagadze, I. K. Surin, M. V. Timoshenko, Yu. V. Usov, V. N. Zhabin, and V. V. Zhulanov

Subjects
Astrophysics, QB460-466, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract The process $$e^+e^-\rightarrow \eta \pi ^0\gamma $$ e + e - → η π 0 γ is studied in the center-of-mass energy range 1.05–2.00 GeV using data with an integrated luminosity of 94.5 $$\hbox {pb}^{-1}$$ pb - 1 collected by the SND detector at the VEPP-2000 $$e^{+}e^{-}$$ e + e - collider. The $$e^+e^-\rightarrow \eta \pi ^0\gamma $$ e + e - → η π 0 γ cross section is measured for the first time. It is shown that the dominant mechanism of this reaction is the transition through the $$\omega \eta $$ ω η intermediate state. The measured cross section of the subprocess $$e^+e^-\rightarrow \omega \eta \rightarrow \eta \pi ^0\gamma $$ e + e - → ω η → η π 0 γ is consistent with previous measurements in the $$e^+e^-\rightarrow \pi ^+\pi ^-\pi ^0\eta $$ e + e - → π + π - π 0 η mode. It is found, with a significance of $$5.6\sigma $$ 5.6 σ , that the process $$e^+e^-\rightarrow \eta \pi ^0\gamma $$ e + e - → η π 0 γ is not completely described by hadronic vector-pseudoscalar intermediate states. The cross section of this missing contribution, which can originate from radiation processes, e. g. $$e^+e^-\rightarrow a_{0}(1450)\gamma $$ e + e - → a 0 ( 1450 ) γ , is measured. It is found to be 15–20 pb in the wide energy range from 1.3 to 1.9 GeV.

Published
2020
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45. Study of dynamics of the process $$e^+e^-\rightarrow \pi ^+\pi ^-\pi ^0$$ e + e - → π + π - π 0 in the energy range 1.15–2.00 GeV

Author

M. N. Achasov, A. Yu. Barnyakov, A. A. Baykov, K. I. Beloborodov, A. V. Berdyugin, D. E. Berkaev, A. G. Bogdanchikov, A. A. Botov, T. V. Dimova, V. P. Druzhinin, V. B. Golubev, A. N. Kirpotin, L. V. Kardapoltsev, A. S. Kasaev, A. G. Kharlamov, I. A. Koop, A. A. Korol, D. P. Kovrizhin, A. S. Kupich, K. A. Martin, N. A. Melnikova, N. Yu. Muchnoy, A. E. Obrazovsky, E. V. Pakhtusova, K. V. Pugachev, D. V. Rabusov, Yu. A. Rogovsky, Y. S. Savchenko, A. I. Senchenko, S. I. Serednyakov, D. N. Shatilov, Yu. M. Shatunov, D. A. Shtol, D. B. Shwartz, Z. K. Silagadze, I. K. Surin, M. V. Timoshenko, Yu. V. Usov, V. N. Zhabin, and V. V. Zhulanov

Subjects
Astrophysics, QB460-466, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract The dynamics of the process $$ e^+e^- \rightarrow \pi ^+\pi ^-\pi ^0 $$ e + e - → π + π - π 0 is studied in the energy region from 1.15 to 2.00 GeV using data accumulated with the SND detector at the VEPP-2000 $$e^+e^-$$ e + e - collider. The Dalitz plot distribution and $$\pi ^+\pi ^-$$ π + π - mass spectrum are analyzed in a model including the intermediate states $$\rho (770)\pi $$ ρ ( 770 ) π , $$\rho (1450)\pi $$ ρ ( 1450 ) π , and $$\omega \pi ^0$$ ω π 0 . As a result, the energy dependences of the $$\rho (770)\pi $$ ρ ( 770 ) π and $$\rho (1450)\pi $$ ρ ( 1450 ) π cross sections and the relative phases between the $$\rho (770)\pi $$ ρ ( 770 ) π amplitude and the $$\rho (1450)\pi $$ ρ ( 1450 ) π and $$\omega \pi ^0$$ ω π 0 amplitudes are obtained. The $$\rho (1450)\pi $$ ρ ( 1450 ) π cross section has a peak in the energy region of the $$\omega (1650)$$ ω ( 1650 ) resonance (1.55–1.75 GeV). In this energy range the contributions of the $$\rho (770)\pi $$ ρ ( 770 ) π and $$\rho (1450)\pi $$ ρ ( 1450 ) π states are of the same order of magnitude. No resonance structure near 1.65 GeV is observed in the $$\rho (770)\pi $$ ρ ( 770 ) π cross section. We conclude that the intermediate state $$\rho (1450)\pi $$ ρ ( 1450 ) π gives a significant contribution to the decay of $$\omega (1650)\rightarrow \pi ^+\pi ^-\pi ^0$$ ω ( 1650 ) → π + π - π 0 , whereas the $$\rho (770)\pi $$ ρ ( 770 ) π mechanism dominates in the decay $$\omega (1420)\rightarrow \pi ^+\pi ^-\pi ^0$$ ω ( 1420 ) → π + π - π 0 .

Published
2020
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46. Study of the process e+e-→ηηγs=1.17--2.00 in the energy range e+e-→ηηγs=1.17--2.00 GeV with the SND detector

Author

Achasov, M. N., Barnyakov, A. Yu., Beloborodov, K. I., Berdyugin, A. V., Berkaev, D. E., Bogdanchikov, A. G., Botov, A. A., Dimova, T. V., Druzhinin, V. P., Kirpotin, A. N., Kardapoltsev, L. V., Kasaev, A. S., Kharlamov, A. G., Koop, I. A., Korol, A. A., Kovrizhin, D. P., Kupich, A. S., Martin, K. A., Melnikova, N. A., Muchnoy, N. Yu., Obrazovsky, A. E., Pakhtusova, E. V., Pugachev, K. V., Rabusov, D. V., Rogovsky, Yu. A., Senchenko, A. I., Serednyakov, S. I., Shatilov, D. N., Shatunov, Yu. M., Shtol, D. A., Shwartz, D. B., Silagadze, Z. K., Surin, I. K., Timoshenko, M. V., Usov, Yu. V., Zhabin, V. N., and Zhulanov, V. V.

Published
2022
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47. Control of electron-electron interaction in graphene by proximity screening

Author

M. Kim, S. G. Xu, A. I. Berdyugin, A. Principi, S. Slizovskiy, N. Xin, P. Kumaravadivel, W. Kuang, M. Hamer, R. Krishna Kumar, R. V. Gorbachev, K. Watanabe, T. Taniguchi, I. V. Grigorieva, V. I. Fal’ko, M. Polini, and A. K. Geim

Subjects
Science
Abstract

Experimental control of electron-electron interactions in materials is challenging. Here, the authors control the interactions by proximity screening with gate dielectrics of nanometer thickness, revealing qualitative changes in concentration and temperature dependences, and validating their analysis using electron hydrodynamics and umklapp scattering approaches.

Published
2020
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48. X-Ray Polarization Observations of BL Lacertae

Author

Riccardo Middei, Ioannis Liodakis, Matteo Perri, Simonetta Puccetti, Elisabetta Cavazzuti, Laura Di Gesu, Steven R. Ehlert, Grzegorz Madejski, Alan P. Marscher, Herman L. Marshall, Fabio Muleri, Michela Negro, Svetlana G. Jorstad, Beatriz Agís-González, Iván Agudo, Giacomo Bonnoli, Maria I. Bernardos, Víctor Casanova, Maya García-Comas, César Husillos, Alessandro Marchini, Alfredo Sota, Pouya M. Kouch, Elina Lindfors, George A. Borman, Evgenia N. Kopatskaya, Elena G. Larionova, Daria A. Morozova, Sergey S. Savchenko, Andrey A. Vasilyev, Alexey V. Zhovtan, Carolina Casadio, Juan Escudero, Ioannis Myserlis, Antonio Hales, Seiji Kameno, Ruediger Kneissl, Hugo Messias, Hiroshi Nagai, Dmitry Blinov, Ioakeim G. Bourbah, Sebastian Kiehlmann, Evangelos Kontopodis, Nikos Mandarakas, Stylianos Romanopoulos, Raphael Skalidis, Anna Vervelaki, Joseph R. Masiero, Dimitri Mawet, Maxwell A. Millar-Blanchaer, Georgia V. Panopoulou, Samaporn Tinyanont, Andrei V. Berdyugin, Masato Kagitani, Vadim Kravtsov, Takeshi Sakanoi, Ryo Imazawa, Mahito Sasada, Yasushi Fukazawa, Koji S. Kawabata, Makoto Uemura, Tsunefumi Mizuno, Tatsuya Nakaoka, Hiroshi Akitaya, Mark Gurwell, Ramprasad Rao, Niccoló Di Lalla, Nicoló Cibrario, Immacolata Donnarumma, Dawoon E. Kim, Nicola Omodei, Luigi Pacciani, Juri Poutanen, Fabrizio Tavecchio, Lucio A. Antonelli, Matteo Bachetti, Luca Baldini, Wayne H. Baumgartner, Ronaldo Bellazzini, Stefano Bianchi, Stephen D. Bongiorno, Raffaella Bonino, Alessandro Brez, Niccoló Bucciantini, Fiamma Capitanio, Simone Castellano, Stefano Ciprini, Enrico Costa, Alessandra De Rosa, Ettore Del Monte, Alessandro Di Marco, Victor Doroshenko, Michal Dovčiak, Teruaki Enoto, Yuri Evangelista, Sergio Fabiani, Riccardo Ferrazzoli, Javier A. Garcia, Shuichi Gunji, Kiyoshi Hayashida, Jeremy Heyl, Wataru Iwakiri, Vladimir Karas, Takao Kitaguchi, Jeffery J. Kolodziejczak, Henric Krawczynski, Fabio La Monaca, Luca Latronico, Simone Maldera, Alberto Manfreda, Frédéric Marin, Andrea Marinucci, Francesco Massaro, Giorgio Matt, Ikuyuki Mitsuishi, C.-Y. Ng, Stephen L. O’Dell, Chiara Oppedisano, Alessandro Papitto, George G. Pavlov, Abel L. Peirson, Melissa Pesce-Rollins, Pierre-Olivier Petrucci, Maura Pilia, Andrea Possenti, Brian D. Ramsey, John Rankin, Ajay Ratheesh, Roger W. Romani, Carmelo Sgró, Patrick Slane, Paolo Soffitta, Gloria Spandre, Toru Tamagawa, Roberto Taverna, Yuzuru Tawara, Allyn F. Tennant, Nicholas E. Thomas, Francesco Tombesi, Alessio Trois, Sergey Tsygankov, Roberto Turolla, Jacco Vink, Martin C. Weisskopf, Kinwah Wu, Fei Xie, and Silvia Zane

Subjects
Relativistic jets, X-ray active galactic nuclei, Active galactic nuclei, Blazars, Spectropolarimetry, Astrophysics, QB460-466
Abstract

Blazars are a class of jet-dominated active galactic nuclei with a typical double-humped spectral energy distribution. It is of common consensus that the synchrotron emission is responsible for the low frequency peak, while the origin of the high frequency hump is still debated. The analysis of X-rays and their polarization can provide a valuable tool to understand the physical mechanisms responsible for the origin of high-energy emission of blazars. We report the first observations of BL Lacertae (BL Lac) performed with the Imaging X-ray Polarimetry Explorer, from which an upper limit to the polarization degree Π _X < 12.6% was found in the 2–8 keV band. We contemporaneously measured the polarization in radio, infrared, and optical wavelengths. Our multiwavelength polarization analysis disfavors a significant contribution of proton-synchrotron radiation to the X-ray emission at these epochs. Instead, it supports a leptonic origin for the X-ray emission in BL Lac.

Published
2022
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49. Study of the Dynamics of the Process \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${e}^{{+}}{e}^{{-}}{\to}{\pi}^{{+}}{\pi}^{{-}}{\pi}^{{0}}$$\end{document} in the Energy Range between 1.15 and 2.00 GeV

Author

Achasov, M. N., Barnyakov, A. Yu., Baykov, A. A., Beloborodov, K. I., Berdyugin, A. V., Bogdanchikov, A. G., Botov, A. A., Golubev, V. B., Dimova, T. V., Druzhinin, V. P., Zhabin, V. N., Zhulanov, V. V., Kardapoltsev, L. V., Kovrizhin, D. P., Korol, A. A., Kupich, A. S., Martin, K. A., Melnikova, N. A., Muchnoi, N. Yu., Obrazovsky, A. E., Pakhtusova, E. V., Pugachev, K. V., Savchenko, Ya. S., Serednyakov, S. I., Silagadze, Z. K., Surin, I. K., Usov, Yu. V., Kharlamov, A. G., and Shtol, D. A.

Published
2020
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50. Search for the Process \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${e}^{+}{e}^{-}\to \eta^{\prime}\gamma$$\end{document} with the SND Detector

Author

Achasov, M. N., Barnyakov, A. Yu., Beloborodov, K. I., Berdyugin, A. V., Berkaev, D. E., Bogdanchikov, A. G., Botov, A. A., Golubev, V. B., Dimova, T. V., Druzhinin, V. P., Zhabin, V. N., Kardapoltsev, L. V., Kasaev, A. S., Kyrpotin, A. N., Kovrizhin, D. P., Koop, I. A., Korol, A. A., Kupich, A. S., Martin, K. A., Melnikova, N. A., Muchnoi, N. Yu., Obrazovskiy, A. E., Otboyev, A. V., Pakhtusova, E. V., Pugachev, K. V., Rogovsky, Yu. A., Savchenko, Ya. S., Senchenko, A. I., Serednyakov, S. I., Silagadze, Z. K., Surin, I. K., Timoshenko, M. V., Usov, Yu. V., Kharlamov, A. G., Shatunov, Yu. M., Shwartz, D. B., and Shtol, D. A.

Published
2020
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