2019, Kokoulin, R. P., Barbashina, N. S., Bogdanov, A. G., Kindin, V. V., Kompaniets, K. G., Petrukhin, A. A., Khomyakov, V. A., Khokhlov, S. S., Shutenko, V. V., Yashin, I. I., Кокоулин, Ростислав Павлович, Барбашина, Наталья Сергеевна, Богданов, Алексей Георгиевич, Киндин, Виктор Владимирович, Компаниец, Константин Георгиевич, Петрухин, Анатолий Афанасьевич, Хохлов, Семен Сергеевич, Шутенко, Виктор Викторович, Яшин, Игорь Иванович

© 2019, Allerton Press, Inc.Abstract: Results are presented from analyzing experimental data on 0.1–10 TeV cascade showers generated by muons in the NEVOD Cherenkov water detector. The procedure for selecting and reconstructing the parameters of events with cascades in the detector volume is discussed. Results are presented from measurements of the zenith angle distribution of cascades for different energies. The measured distributions are compared to results from calculations.

2019, Mannocchi, G., Trinchero, G., Yurina, E. A., Barbashina, N. S., Bogdanov, A. G., Khokhlov, S. S., Kindin, V. V., Kokoulin, R. P., Kompaniets, K. G., Petrukhin, A. A., Shutenko, V. V., Yashin, I. I., Юрина, Екатерина Александровна, Барбашина, Наталья Сергеевна, Богданов, Алексей Георгиевич, Хохлов, Семен Сергеевич, Киндин, Виктор Владимирович, Кокоулин, Ростислав Павлович, Компаниец, Константин Георгиевич, Петрухин, Анатолий Афанасьевич, Шутенко, Виктор Викторович, Яшин, Игорь Иванович

© 2019, Pleiades Publishing, Ltd.Investigations of the energy loss of muon bundles are being conducted at the Experimental complex NEVOD. Such investigations are directed to detailed study of “muon puzzle” (the excess of multi-muon events observed in several cosmic ray experiments at ultra-high energies). Results of measurements of the muon bundle energy deposit during a long period of observations in primary cosmic ray energy range 10–1000 PeV have been obtained and have been compared with simulations performed on the basis of the CORSIKA code.

2020, Chernov, D. V , Kindin, V. V., Kompaniets, K. G., Mannocchi, G., Trinchero, G., Shutenko, V. V. , Yurina, E. A., Петрухин, Анатолий Афанасьевич, Задеба, Егор Александрович, Яшин, Игорь Иванович, Хохлов, Семен Сергеевич, Кокоулин, Ростислав Павлович, Богданов, Алексей Георгиевич, Барбашина, Наталья Сергеевна, Bogdanov, A. G., Barbashina, N. S., Kokoulin, R. P., Petrukhin, A. A., Yashin, I. I., Zadeba, E. A., Khokhlov, S. S., Шутенко, Виктор Викторович, Компаниец, Константин Георгиевич, Киндин, Виктор Владимирович

Data of NEVOD-DECOR experiment on investigations of inclined cosmic ray muon bundles for a long time period (May 2012 – May 2020) are presented. Their comparison with the results of calculations based on simulations of extensive air shower hadron and muon components is carried out. The analysis showed that the observed intensity of muon bundles at primary particle energies of about 1018 eV and higher can be compatible with the expectation only under the assumption of an extremely heavy mass composition of cosmic rays. On the contrary, measurements of the depth of the shower maximum in the atmosphere in the experiments using air fluorescence technique, favour a light mass composition of primary cosmic rays at these energies.

2021, Yurina, E. A. , Kindin, V. V. , Kompaniets, K. G. , Mannocchi, G., Trinchero, G., Shutenko, V. V. , Хохлов, Семен Сергеевич, Яшин, Игорь Иванович, Петрухин, Анатолий Афанасьевич, Кокоулин, Ростислав Павлович, Богданов, Алексей Георгиевич, Барбашина, Наталья Сергеевна, Yashin, I. I., Khokhlov, S. S., Petrukhin, A. A., Kokoulin, R. P., Bogdanov, A. G., Barbashina, N. S., Киндин, Виктор Владимирович, Компаниец, Константин Георгиевич, Шутенко, Виктор Викторович

Allerton Press, Inc.Abstract: The existence of an excessive number of multimuon events observed in many experiments at ultrahigh EAS energies (above 1017 eV) relative to calculations cannot be explained using modern models of hadronic interactions. One way of solving the problem of muon excess is to study the energy characteristics of the EAS muon component. Results are presented from measurements of muon bundle energy characteristics over 7 years of observations. The experimental dependences are compared to results from simulation done with the CORSIKA software package.

2019, Mannocchi, G., Trinchero, G., Amelchakov, M. B., Barbashina, N. S., Bogdanov, A. G., Gromushkin, D. M., Zadeba, E. A., Kindin, V. V., Kokoulin, R. P., Kompaniets, K. G., Chiavassa, A., Likiy, O. I., Petrukhin, A. A., Stenkin, Y. V., Khokhlov, S. S., Shulzhenko, I. A., Shutenko, V. V., Yurin, K. O., Yashin, I. I., Амельчаков, Михаил Борисович, Барбашина, Наталья Сергеевна, Богданов, Алексей Георгиевич, Громушкин, Дмитрий Михайлович, Задеба, Егор Александрович, Киндин, Виктор Владимирович, Кокоулин, Ростислав Павлович, Компаниец, Константин Георгиевич, Петрухин, Анатолий Афанасьевич, Стенькин, Юрий Васильевич, Хохлов, Семен Сергеевич, Шульженко, Иван Андреевич, Шутенко, Виктор Викторович, Яшин, Игорь Иванович

© 2019, Allerton Press, Inc.Abstract: The NEVOD experimental complex was created at MEPhI. It includes several facilities for studying the electron–photon, muon, and hadron components of the EAS in the energy range of 1 PeV to 1 EeV. This work presents the first results for two months of the joint operation of five facilities (NEVOD-EAS, CWD, CTS, PRISMA-32, and DECOR). The problems of synchronizing the facilities and selecting joint events are considered. The experimental data of these facilities are analyzed for different components of the EAS in overlapping energy ranges.

2019, Kokoulin, R. P., Barbashina, N. S., Bogdanov, A. G., Khokhlov, S. S., Khomyakov, V. A., Kindin, V. V., Kompaniets, K. G., Petrukhin, A. A., Shutenko, V. V., Yashin, I. I., Yurina, E. A., Кокоулин, Ростислав Павлович, Барбашина, Наталья Сергеевна, Богданов, Алексей Георгиевич, Хохлов, Семен Сергеевич, Киндин, Виктор Владимирович, Компаниец, Константин Георгиевич, Петрухин, Анатолий Афанасьевич, Шутенко, Виктор Викторович, Яшин, Игорь Иванович, Юрина, Екатерина Александровна

An experiment on the measurements of the energy deposit of inclined cosmic ray muon bundles is being conducted at the experimental complex NEVOD (MEPhI). The complex includes the Cherenkov water calorimeter with a volume of 2000 m(3) and the coordinate-tracking detector DECOR with a total area of 70 m(2). The DECOR data are used to determine the local muon densities in the bundle events and their arrival directions, while the energy deposits (and hence the average muon energy loss) are evaluated from the Cherenkov calorimeter response. Average energy loss carries information about the mean muon energy in the bundles. The detection of the bundles in a wide range of muon multiplicities and zenith angles gives the opportunity to explore the energy range of primary cosmic ray particles from about 10 to 1000 PeV in the frame of a single experiment with a relatively small compact setup. Experimental results on the dependence of the muon bundle energy deposit on the zenith angle and the local muon density are presented and compared with expectations based on simulations of the EAS muon component with the CORSIKA code.

2021, Kindin, V. V. , Kompaniets, K. G., Mannocchi, G. , Shutenko, V. V. , Trinchero, G. , Yurina, E. A. , Яшин, Игорь Иванович, Задеба, Егор Александрович, Петрухин, Анатолий Афанасьевич, Хохлов, Семен Сергеевич, Кокоулин, Ростислав Павлович, Богданов, Алексей Георгиевич, Барбашина, Наталья Сергеевна, Barbashina, N. S., Bogdanov, A. G., Khokhlov, S. S., Petrukhin, A. A., Yashin, I. I., Zadeba, E. A., Kokoulin, R. P., Киндин, Виктор Владимирович, Компаниец, Константин Георгиевич, Шутенко, Виктор Викторович

Data of the NEVOD-DECOR experiment on investigations of inclined cosmic ray muon bundles for a long time period (May 2012 – March 2021) are presented. Their comparison with the results of calculations based on simulations of EAS muon component allows one to study the behavior of the energy spectrum and mass composition of primary cosmic rays and/or to check the validity of hadron interaction models in a wide energy range from about 1016 to more than 1018 eV. The analysis showed that the observed intensity of muon bundles at primary particle energies of about 1018 eV and higher can be compatible with the expectation only under the assumption of an extremely heavy mass composition of cosmic rays. This conclusion is consistent with data of a number of other experiments investigating the muon component of air showers at ultra-high energies. On the contrary, measurements of the depth of the shower maximum in the atmosphere (Xmax) in the experiments using air fluorescence technique favor a light mass composition of primary cosmic rays at these energies. This contradiction (so-called “muon puzzle”) cannot be resolved without serious changes of the existing hadron interaction models.

2019, Mannocchi, G., Saavedra, O., Trinchero, G., Yurina, E. A., Barbashina, N. S., Bogdanov, A. G., Kindin, V. V., Kokoulin, R. P., Kompaniets, K. G., Petrukhin, A. A., Khomyakov, V. A., Khokhlov, S. S., Shutenko, V. V., Yashin, I. I., Юрина, Екатерина Александровна, Барбашина, Наталья Сергеевна, Богданов, Алексей Георгиевич, Киндин, Виктор Владимирович, Кокоулин, Ростислав Павлович, Компаниец, Константин Георгиевич, Петрухин, Анатолий Афанасьевич, Хохлов, Семен Сергеевич, Шутенко, Виктор Викторович, Яшин, Игорь Иванович

© 2019, Allerton Press, Inc.Abstract: Energy characteristics of the muon component of extensive air showers (EASes) are investigated at the NEVOD experimental complex in order to solve the problem of a detected excess of muons in EASes at ultrahigh energies, relative to simulation results. The dependences of the energy deposit of muon bundles on the zenith angle and the local muon density are obtained for primary energies of 10–1000 PeV. The results from comparing the data to simulations performed with the CORSIKA program are presented.

2022, Шульженко, Иван Андреевич, Яшин, Игорь Иванович, Хохлов, Семен Сергеевич, Кокоулин, Ростислав Павлович, Громушкин, Дмитрий Михайлович, Богданов, Алексей Георгиевич, Петрухин, Анатолий Афанасьевич, Барбашина, Наталья Сергеевна, Pasyuk, N. A., Kokoulin, R. P., Kindin, V. V., Khokhlov, S. S., Gromushkin, D. M., Bogdanov, A. G., Barbashina, N. S., Shutenko, V. V., Shulzhenko, I. A., Petrukhin, A. A., Yashin, I. I., Amelchakov, M. B., Kompaniets, K. G., Konovalova, A. Y., Ovchinnikov, V. V., Yurin, K. O., Пасюк, Никита Александрович, Шутенко, Виктор Викторович, Овчинников, Вячеслав Васильевич, Коновалова, Алена Юрьевна, Компаниец, Константин Георгиевич, Киндин, Виктор Владимирович, Амельчаков, Михаил Борисович

The Experimental complex NEVOD includes several different setups for studying various components of extensive air showers (EAS) in the energy range from 1010 to 1018eV. The NEVOD-EAS array for detection of the EAS electron–photon component began its data taking in 2018. It is a distributed system of scintillation detectors installed over an area of about 104 m2. A distinctive feature of this array is its cluster organization with different-altitude layout of the detecting elements. The main goal of the NEVOD-EAS array is to obtain an estimation of the primary particle energy for events measured by various detectors of the Experimental complex NEVOD. This paper describes the design, operation principles and data processing of the NEVOD-EAS array. The criteria for the event selection and the accuracy of the EAS parameters reconstruction obtained on the simulated events are discussed. The results of the preliminary analysis of experimental data obtained during a half-year operation are presented.

2023, Yurina, E. A., Vorobev, V. S. , Kindin, V. V. , Kompaniets, K. G., Konovalova, A. Yu. , Mannocchi, G. , Trinchero, G. , Shutenko, V. V., Богданов, Алексей Георгиевич, Кокоулин, Ростислав Павлович, Яшин, Игорь Иванович, Хохлов, Семен Сергеевич, Петрухин, Анатолий Афанасьевич, Барбашина, Наталья Сергеевна, Khokhlov, S. S., Yashin, I. I., Kokoulin, R. P., Bogdanov, A. G., Barbashina, N. S., Petrukhin, A. A., Киндин, Виктор Владимирович, Шутенко, Виктор Викторович, Коновалова, Алена Юрьевна, Компаниец, Константин Георгиевич

Results are presented from measuring the energy characteristics of muon bundles in inclined extensive air showers in the NEVOD-DECOR experiment. Estimates of the average energy of muons in the bundles are obtained in the 10 to 1000 PeV range of primary particle energies and compared to values calculated under different assumptions about the composition of cosmic radiation and models of hadronic interactions. An excess of experimental values of the average muon energy relative to calculations is found for high local densities corresponding to primary particle energies above 100 PeV.