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23 results on '"Nikolaev, A. S."'

1. Track-Like Event Analysis at the Baikal-GVD Neutrino Telescope

Author

Aynutdinov, V. M., Allakhverdyan, V. A., Avrorin, A. D., Avrorin, A. V., Bardačová, Z., Belolaptikov, I. A., Bondarev, E. A., Borina, I. V., Budnev, N. M., Chadymov, V. A., Chepurnov, A. S., Dik, V. Y., Domogatsky, G. V., Doroshenko, A. A., Dvornický, R., Dyachok, A. N., Dzhilkibaev, Zh. -A. M., Eckerová, E., Elzhov, T. V., Fajt, L., Fomin, V. N., Gafarov, A. R., Golubkov, K. V., Gorshkov, N. S., Gress, T. I., Kebkal, K. G., Kharuk, I. V., Khramov, E. V., Kolbin, M. M., Koligaev, S. O., Konischev, K. V., Korobchenko, A. V., Koshechkin, A. P., Kozhin, V. A., Kruglov, M. V., Kulepov, V. F., Lemeshev, Y. E., Milenin, M. B., Mirgazov, R. R., Naumov, D. V., Nikolaev, A. S., Petukhov, D. P., Pliskovsky, E. N., Rozanov, M. I., Ryabov, E. V., Safronov, G. B., Seitova, D., Shaybonov, B. A., Shelepov, M. D., Shilkin, S. D., Shirokov, E. V., Šimkovic, F., Sirenko, A. E., Skurikhin, A. V., Solovjev, A. G., Sorokovikov, M. N., Štekl, I., Stromakov, A. P., Suvorova, O. V., Tabolenko, V. A., Ulzutuev, B. B., Yablokova, Y. V., Zaborov, D. N., Zavyalov, S. I., and Zvezdov, D. Y.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Physics - Instrumentation and Detectors
Abstract

Reconstructed tracks of muons produced in neutrino interactions provide the precise probe for the neutrino direction. Therefore, track-like events are a powerful tool to search for neutrino point sources. Recently, Baikal-GVD has demonstrated the first sample of low-energy neutrino candidate events extracted from the data of the season 2019 in a so-called single-cluster analysis - treating each cluster as an independent detector. In this paper, the extension of the track-like event analysis to a wider data set is discussed and the first high-energy track-like events are demonstrated. The status of multi-cluster track reconstruction and that of the event analysis are also discussed., Comment: Presented at the 38th International Cosmic Ray Conference (ICRC 2023)

Published
2023

2. Atmospheric muon suppression for Baikal-GVD cascade analysis

Author

Aynutdinov, V. M., Allakhverdyan, V. A., Avrorin, A. D., Avrorin, A. V., Bardačová, Z., Belolaptikov, I. A., Bondarev, E. A., Borina, I. V., Budnev, N. M., Chadymov, V. A., Chepurnov, A. S., Dik, V. Y., Domogatsky, G. V., Doroshenko, A. A., Dvornický, R., Dyachok, A. N., Dzhilkibaev, Zh. -A. M., Eckerová, E., Elzhov, T. V., Fajt, L., Fomin, V. N., Gafarov, A. R., Golubkov, K. V., Gorshkov, N. S., Gress, T. I., Kebkal, K. G., Kharuk, I. V., Khramov, E. V., Kolbin, M. M., Koligaev, S. O., Konischev, K. V., Korobchenko, A. V., Koshechkin, A. P., Kozhin, V. A., Kruglov, M. V., Kulepov, V. F., Lemeshev, Y. E., Milenin, M. B., Mirgazov, R. R., Naumov, D. V., Nikolaev, A. S., Petukhov, D. P., Pliskovsky, E. N., Rozanov, M. I., Ryabov, E. V., Safronov, G. B., Seitova, D., Shaybonov, B. A., Shelepov, M. D., Shilkin, S. D., Shirokov, E. V., Šimkovic, F., Sirenko, A. E., Skurikhin, A. V., Solovjev, A. G., Sorokovikov, M. N., Štekl, I., Stromakov, A. P., Suvorova, O. V., Tabolenko, V. A., Ulzutuev, B. B., Yablokova, Y. V., Zaborov, D. N., Zavyalov, S. I., and Zvezdov, D. Y.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Physics - Instrumentation and Detectors
Abstract

Baikal-GVD (Gigaton Volume Detector) is a neutrino telescope installed at a depth of 1366 m in Lake Baikal. The expedition of 2023 brought the number of optical modules in the array up to 3492 (including experimental strings). These optical modules detect the Cherenkov radiation from secondary charged particles coming from the neutrino interactions. Neutrinos produce different kinds of topologically distinct light signatures. Charged current muon neutrino interactions create an elongated track in the water. Charged and neutral current interactions of other neutrino flavors yield hadronic and electromagnetic cascades. The background in the neutrino cascade channel arises mainly due to discrete stochastic energy losses produced along atmospheric muon tracks. In this paper, a developed algorithm for the cascade event selection is presented., Comment: Presented at the 38th International Cosmic Ray Conference (ICRC 2023)

Published
2023
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3. Double cascade reconstruction in the Baikal-GVD neutrino telescope

Author

Aynutdinov, V. M., Allakhverdyan, V. A., Avrorin, A. D., Avrorin, A. V., Bardačová, Z., Belolaptikov, I. A., Bondarev, E. A., Borina, I. V., Budnev, N. M., Chadymov, V. A., Chepurnov, A. S., Dik, V. Y., Domogatsky, G. V., Doroshenko, A. A., Dvornický, R., Dyachok, A. N., Dzhilkibaev, Zh. -A. M., Eckerová, E., Elzhov, T. V., Fajt, L., Fomin, V. N., Gafarov, A. R., Golubkov, K. V., Gorshkov, N. S., Gress, T. I., Kebkal, K. G., Kharuk, I. V., Khramov, E. V., Kolbin, M. M., Koligaev, S. O., Konischev, K. V., Korobchenko, A. V., Koshechkin, A. P., Kozhin, V. A., Kruglov, M. V., Kulepov, V. F., Lemeshev, Y. E., Milenin, M. B., Mirgazov, R. R., Naumov, D. V., Nikolaev, A. S., Petukhov, D. P., Pliskovsky, E. N., Rozanov, M. I., Ryabov, E. V., Safronov, G. B., Seitova, D., Shaybonov, B. A., Shelepov, M. D., Shilkin, S. D., Shirokov, E. V., Šimkovic, F., Sirenko, A. E., Skurikhin, A. V., Solovjev, A. G., Sorokovikov, M. N., Štekl, I., Stromakov, A. P., Suvorova, O. V., Tabolenko, V. A., Ulzutuev, B. B., Yablokova, Y. V., Zaborov, D. N., Zavyalov, S. I., and Zvezdov, D. Y.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Physics - Instrumentation and Detectors
Abstract

Baikal Gigaton Volume Detector is a cubic kilometer scale neutrino telescope under construction in Lake Baikal. As of July 2023, Baikal-GVD consists of 96 fully deployed strings resulting in 3456 optical modules installed. The observation of neutrinos is based on detection of Cherenkov radiation emitted by the products of neutrino interactions. In this contribution, description of the double cascade reconstruction technique as well as evaluation of precision of this algorithm is given., Comment: Presented at the 38th International Cosmic Ray Conference (ICRC 2023)

Published
2023
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4. Improving the efficiency of cascade detection by the Baikal-GVD neutrino telescope

Author

Aynutdinov, V. M., Allakhverdyan, V. A., Avrorin, A. D., Avrorin, A. V., Bardačová, Z., Belolaptikov, I. A., Bondarev, E. A., Borina, I. V., Budnev, N. M., Chadymov, V. A., Chepurnov, A. S., Dik, V. Y., Domogatsky, G. V., Doroshenko, A. A., Dvornický, R., Dyachok, A. N., Dzhilkibaev, Zh. -A. M., Eckerová, E., Elzhov, T. V., Fajt, L., Fomin, V. N., Gafarov, A. R., Golubkov, K. V., Gorshkov, N. S., Gress, T. I., Kebkal, K. G., Kharuk, I. V., Khramov, E. V., Kolbin, M. M., Koligaev, S. O., Konischev, K. V., Korobchenko, A. V., Koshechkin, A. P., Kozhin, V. A., Kruglov, M. V., Kulepov, V. F., Lemeshev, Y. E., Milenin, M. B., Mirgazov, R. R., Naumov, D. V., Nikolaev, A. S., Petukhov, D. P., Pliskovsky, E. N., Rozanov, M. I., Ryabov, E. V., Safronov, G. B., Seitova, D., Shaybonov, B. A., Shelepov, M. D., Shilkin, S. D., Shirokov, E. V., Šimkovic, F., Sirenko, A. E., Skurikhin, A. V., Solovjev, A. G., Sorokovikov, M. N., Štekl, I., Stromakov, A. P., Suvorova, O. V., Tabolenko, V. A., Ulzutuev, B. B., Yablokova, Y. V., Zaborov, D. N., Zavyalov, S. I., and Zvezdov, D. Y.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Physics - Instrumentation and Detectors
Abstract

The deployment of the Baikal-GVD deep underwater neutrino telescope is in progress now. About 3500 deep underwater photodetectors (optical modules) arranged into 12 clusters are operating in Lake Baikal. For increasing the efficiency of cascade-like neutrino event detection, the telescope deployment scheme was slightly changed. Namely, the inter-cluster distance was reduced for the newly deployed clusters and additional string of optical modules are added between the clusters. The first inter-cluster string was installed in 2022 and two such strings were installed in 2023. This paper presents a Monte Carlo estimate of the impact of these configuration changes on the cascade detection efficiency as well as technical implementation and results of in-situ tests of the inter-cluster strings., Comment: Presented at the 38th International Cosmic Ray Conference (ICRC 2023)

Published
2023
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5. Diffuse neutrino flux measurements with the Baikal-GVD neutrino telescope

Author

Aynutdinov, V. M., Allakhverdyan, V. A., Avrorin, A. D., Avrorin, A. V., Bardačová, Z., Belolaptikov, I. A., Bondarev, E. A., Borina, I. V., Budnev, N. M., Chadymov, V. A., Chepurnov, A. S., Dik, V. Y., Domogatsky, G. V., Doroshenko, A. A., Dvornický, R., Dyachok, A. N., Dzhilkibaev, Zh. -A. M., Eckerová, E., Elzhov, T. V., Fajt, L., Fomin, V. N., Gafarov, A. R., Golubkov, K. V., Gorshkov, N. S., Gress, T. I., Kebkal, K. G., Kharuk, I. V., Khramov, E. V., Kolbin, M. M., Koligaev, S. O., Konischev, K. V., Korobchenko, A. V., Koshechkin, A. P., Kozhin, V. A., Kruglov, M. V., Kulepov, V. F., Lemeshev, Y. E., Milenin, M. B., Mirgazov, R. R., Naumov, D. V., Nikolaev, A. S., Petukhov, D. P., Pliskovsky, E. N., Rozanov, M. I., Ryabov, E. V., Safronov, G. B., Seitova, D., Shaybonov, B. A., Shelepov, M. D., Shilkin, S. D., Shirokov, E. V., Šimkovic, F., Sirenko, A. E., Skurikhin, A. V., Solovjev, A. G., Sorokovikov, M. N., Štekl, I., Stromakov, A. P., Suvorova, O. V., Tabolenko, V. A., Ulzutuev, B. B., Yablokova, Y. V., Zaborov, D. N., Zavyalov, S. I., Zvezdov, D. Y., Kosogorov, N. A., Kovalev, Y. Y., Lipunova, G. V., Plavin, A. V., Semikoz, D. V., and Troitsky, S. V.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Baikal-GVD is a next generation, kilometer-scale neutrino telescope currently under construction in Lake Baikal. GVD consists of multi-megaton subarrays (clusters) and is designed for the detection of astrophysical neutrino fluxes at energies from a few TeV up to 100 PeV. The large detector volume and modular design of Baikal-GVD allows for the measurements of the astrophysical diffuse neutrino flux to be performed already at early phases of the array construction. We present here recent results of the measurements on the diffuse cosmic neutrino flux obtained with the Baikal-GVD neutrino telescope using cascade-like events., Comment: Presented at the 38th International Cosmic Ray Conference (ICRC 2023)

Published
2023
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6. Large neutrino telescope Baikal-GVD: recent status

Author

Aynutdinov, V. M., Allakhverdyan, V. A., Avrorin, A. D., Avrorin, A. V., Bardačová, Z., Belolaptikov, I. A., Bondarev, E. A., Borina, I. V., Budnev, N. M., Chadymov, V. A., Chepurnov, A. S., Dik, 5 V. Y., Domogatsky, G. V., Doroshenko, A. A., Dvornický, R., Dyachok, A. N., Dzhilkibaev, Zh. -A. M., Eckerová, E., Elzhov, T. V., Fajt, L., Fomin, V. N., Gafarov, A. R., Golubkov, K. V., Gorshkov, N. S., Gress, T. I., Kebkal, K. G., Kharuk, I. V., Khramov, E. V., Kolbin, M. M., Koligaev, S. O., Konischev, K. V., Korobchenko, A. V., Koshechkin, A. P., Kozhin, V. A., Kruglov, M. V., Kulepov, V. F., Lemeshev, Y. E., Milenin, M. B., Mirgazov, R. R., Naumov, D. V., Nikolaev, A. S., Petukhov, D. P., Pliskovsky, E. N., Rozanov, M. I., Ryabov, E. V., Safronov, G. B., Seitova, D., Shaybonov, B. A., Shelepov, M. D., Shilkin, S. D., Shirokov, E. V., Šimkovic, F., Sirenko, A. E., Skurikhin, A. V., Solovjev, A. G., Sorokovikov, M. N., Štekl, I., Stromakov, A. P., Suvorova, O. V., Tabolenko, V. A., Ulzutuev, B. B., Yablokova, Y. V., Zaborov, D. N., Zavyalov, S. I., and Zvezdov, D. Y.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Phenomenology
Abstract

The Baikal-GVD is a deep-underwater neutrino telescope being constructed in Lake Baikal. After the winter 2023 deployment campaign the detector consists of 3456 optical modules installed on 96 vertical strings. The status of the detector and progress in data analysis are discussed in present report. The Baikal-GVD data collected in 2018-2022 indicate the presence of cosmic neutrino flux in high-energy cascade events consistent with observations by the IceCube neutrino telescope. Analysis of track-like events results in identification of first high-energy muon neutrino candidates. These and other results from 2018-2022 data samples are reviewed in this report.

Published
2023
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7. Monitoring of optical properties of deep waters of Lake Baikal in 2021-2022

Author

Aynutdinov, V. M., Allakhverdyan, V. A., Avrorin, A. D., Avrorin, A. V., Bardačová, Z., Belolaptikov, I. A., Bondarev, E. A., Borina, I. V., Budnev, N. M., Chadymov, V. A., Chepurnov, A. S., Dik, 5 V. Y., Domogatsky, G. V., Doroshenko, A. A., Dvornický, 0 R., Dyachok, A. N., Dzhilkibaev, Zh. -A. M., Eckerová, E., Elzhov, T. V., Fajt, L., Fomin, V. N., Gafarov, A. R., Golubkov, K. V., Gorshkov, N. S., Gress, T. I., Kebkal, K. G., Kharuk, I. V., Khramov, E. V., Kolbin, M. M., Koligaev, S. O., Konischev, K. V., Korobchenko, A. V., Koshechkin, A. P., Kozhin, V. A., Kruglov, M. V., Kulepov, V. F., Lemeshev, Y. E., Milenin, M. B., Mirgazov, R. R., Naumov, D. V., Nikolaev, A. S., Petukhov, D. P., Pliskovsky, E. N., Rozanov, M. I., Ryabov, E. V., Safronov, G. B., Seitova, D., Shaybonov, B. A., Shelepov, M. D., Shilkin, S. D., Shirokov, E. V., Šimkovic, F., Sirenko, A. E., Skurikhin, A. V., Solovjev, A. G., Sorokovikov, M. N., Štekl, I., Stromakov, A. P., Suvorova, O. V., Tabolenko, V. A., Ulzutuev, B. B., Yablokova, Y. V., Zaborov, D. N., Zavyalov, S. I., and Zvezdov, D. Y.

Subjects
High Energy Physics - Phenomenology
Abstract

We present the results of the two-year (2021-2022) monitoring of absorption and scattering lengths of light with wavelength 400-620 nm within the effective volume of the deep underwater neutrino telescope Baikal-GVD, which were measured by a device Baikal-5D No.2. The Baikal-5D No.2. was installed during the 2021 winter expedition at a depth of 1180 m. The absorption and scattering lengths were measured every week in 9 spectral points. The device Baikal-5D No.2 also has the ability to measure detailed scattering and absorption spectra. The data obtained make it possible to estimate the range of changes in the absorption and scattering lengths over a sufficiently long period of time and to investigate the relationship between the processes of changes in absorption and scattering. An analysis was made of changes in absorption and scattering spectra for the period 2021-2022.

Published
2023
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8. Studies of the ambient light of deep Baikal waters with Baikal-GVD

Author

Aynutdinov, V. M., Allakhverdyan, V. A., Avrorin, A. D., Avrorin, A. V., Bardačová, Z., Belolaptikov, I. A., Bondarev, E. A., Borina, I. V., Budnev, N. M., Chadymov, V. A., Chepurnov, A. S., Dik, 5 V. Y., Domogatsky, G. V., Doroshenko, A. A., Dvornický, 0 R., Dyachok, A. N., Dzhilkibaev, Zh. -A. M., Eckerová, E., Elzhov, T. V., Fajt, L., Fomin, V. N., Gafarov, A. R., Golubkov, K. V., Gorshkov, N. S., Gress, T. I., Kebkal, K. G., Kharuk, I. V., Khramov, E. V., Kolbin, M. M., Koligaev, S. O., Konischev, K. V., Korobchenko, A. V., Koshechkin, A. P., Kozhin, V. A., Kruglov, M. V., Kulepov, V. F., Lemeshev, Y. E., Milenin, M. B., Mirgazov, R. R., Naumov, D. V., Nikolaev, A. S., Petukhov, D. P., Pliskovsky, E. N., Rozanov, M. I., Ryabov, E. V., Safronov, G. B., Seitova, D., Shaybonov, B. A., Shelepov, M. D., Shilkin, S. D., Shirokov, E. V., Šimkovic, F., Sirenko, A. E., Skurikhin, A. V., Solovjev, A. G., Sorokovikov, M. N., Štekl, I., Stromakov, A. P., Suvorova, O. V., Tabolenko, V. A., Ulzutuev, B. B., Yablokova, Y. V., Zaborov, D. N., Zavyalov, S. I., and Zvezdov, D. Y.

Subjects
High Energy Physics - Phenomenology, Physics - Instrumentation and Detectors
Abstract

The Baikal-GVD neutrino detector is a deep-underwater neutrino telescope under construction and recently after the winter 2023 deployment it consists of 3456 optical modules attached on 96 vertical strings. This 3-dimensional array of photo-sensors allows to observe ambient light in the vicinity of the Baikal-GVD telescope that is associated mostly with water luminescence. Results on time and space variations of the luminescent activity are reviewed based on data collected in 2018-2022.

Published
2023
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9. Time Calibration of the Baikal-GVD Neutrino Telescope with Atmospheric Muons

Author

Aynutdinov, V. M., Allakhverdyan, V. A., Avrorin, A. D., Avrorin, A. V., Bardačová, Z., Belolaptikov, I. A., Bondarev, E. A., Borina, I. V., Budnev, N. M., Chadymov, V. A., Chepurnov, A. S., Dik, V. Y., Domogatsky, G. V., Doroshenko, A. A., Dvornický, R., Dyachok, A. N., Dzhilkibaev, Zh. -A. M., Eckerová, E., Elzhov, T. V., Fajt, L., Fomin, V. N., Gafarov, A. R., Golubkov, K. V., Gorshkov, N. S., Gress, T. I., Kebkal, K. G., Kharuk, I. V., Khramov, E. V., Kolbin, M. M., Koligaev, S. O., Konischev, K. V., Korobchenko, A. V., Koshechkin, A. P., Kozhin, V. A., Kruglov, M. V., Kulepov, V. F., Lemeshev, Y. E., Milenin, M. B., Mirgazov, R. R., Naumov, D. V., Nikolaev, A. S., Petukhov, D. P., Pliskovsky, E. N., Rozanov, M. I., Ryabov, E. V., Safronov, G. B., Seitova, D., Shaybonov, B. A., Shelepov, M. D., Shilkin, S. D., Shirokov, E. V., Šimkovic, F., Sirenko, A. E., Skurikhin, A. V., Solovjev, A. G., Sorokovikov, M. N., Štekl, I., Stromakov, A. P., Suvorova, O. V., Tabolenko, V. A., Ulzutuev, B. B., Yablokova, Y. V., Zaborov, D. N., Zavyalov, S. I., and Zvezdov, D. Y.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Physics - Instrumentation and Detectors, 85
Abstract

We present a new procedure for time calibration of the Baikal-GVD neutrino telescope. The track reconstruction quality depends on accurate measurements of arrival times of Cherenkov photons. Therefore, it is crucial to achieve a high precision in time calibration. For that purpose, in addition to other calibration methods, we employ a new procedure using atmospheric muons reconstructed in a single-cluster mode. The method is based on iterative determination of effective time offsets for each optical module. This paper focuses on the results of the iterative reconstruction procedure with time offsets from the previous iteration and the verification of the method developed. The theoretical muon calibration precision is estimated to be around 1.5-1.6ns., Comment: 38th International Cosmic Ray Conference (ICRC2023)

Published
2023

10. Baikal-GVD Real-Time Data Processing and Follow-Up Analysis of GCN Notices

Author

Aynutdinov, V. M., Allakhverdyan, V. A., Avrorin, A. D., Avrorin, A. V., Bardačová, Z., Belolaptikov, I. A., Bondarev, E. A., Borina, I. V., Budnev, N. M., Chadymov, V. A., Chepurnov, A. S., Dik, V. Y., Domogatsky, G. V., Doroshenko, A. A., Dvornický, R., Dyachok, A. N., Dzhilkibaev, Zh. -A. M., Eckerová, E., Elzhov, T. V., Fajt, L., Fomin, V. N., Gafarov, A. R., Golubkov, K. V., Gorshkov, N. S., Gress, T. I., Kebkal, K. G., Kharuk, I. V., Khramov, E. V., Kolbin, M. M., Koligaev, S. O., Konischev, K. V., Korobchenko, A. V., Koshechkin, A. P., Kozhin, V. A., Kruglov, M. V., Kulepov, V. F., Lemeshev, Y. E., Milenin, M. B., Mirgazov, R. R., Naumov, D. V., Nikolaev, A. S., Petukhov, D. P., Pliskovsky, E. N., Rozanov, M. I., Ryabov, E. V., Safronov, G. B., Seitova, D., Shaybonov, B. A., Shelepov, M. D., Shilkin, S. D., Shirokov, E. V., Šimkovic, F., Sirenko, A. E., Skurikhin, A. V., Solovjev, A. G., Sorokovikov, M. N., Štekl, I., Stromakov, A. P., Suvorova, O. V., Tabolenko, V. A., Ulzutuev, B. B., Yablokova, Y. V., Zaborov, D. N., Zavyalov, S. I., and Zvezdov, D. Y.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The Baikal-GVD alert system was launched at the beginning of 2021. There are alerts for muon neutrinos (long upward-going track-like events) and all-flavour neutrinos (high-energy cascades). The system is able to get a preliminary response to external alerts with a temporal delay of about 3-10 minutes. The Baikal-GVD data processing and the results of the follow-up procedure are described. We report on the analysis of the coincidence in time and direction between the Baikal-GVD cascade GVD20211208CA with an estimated energy of 43 TeV and the announced alert IceCube211208A possibly associated with a flaring state of the blazar PKS 0735+178., Comment: 9 pages, 5 figures

Published
2023
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11. Baikal-GVD Astrophysical Neutrino Candidate near the Blazar TXS~0506+056

Author

Aynutdinov, V. M., Allakhverdyan, V. A., Avrorin, A. D., Avrorin, A. V., Bardačová, Z., Belolaptikov, I. A., Bondarev, E. A., Borina, I. V., Budnev, N. M., Chadymov, V. A., Chepurnov, A. S., Dik, V. Y., Domogatsky, G. V., Doroshenko, A. A., Dvornický, R., Dyachok, A. N., Dzhilkibaev, Zh. -A. M., Eckerová, E., Elzhov, T. V., Fajt, L., Fomin, V. N., Gafarov, A. R., Golubkov, K. V., Gorshkov, N. S., Gress, T. I., Kebkal, K. G., Kharuk, I. V., Khramov, E. V., Kolbin, M. M., Koligaev, S. O., Konischev, K. V., Korobchenko, A. V., Koshechkin, A. P., Kozhin, V. A., Kruglov, M. V., Kulepov, V. F., Lemeshev, Y. E., Milenin, M. B., Mirgazov, R. R., Naumov, D. V., Nikolaev, A. S., Petukhov, D. P., Pliskovsky, E. N., Rozanov, M. I., Ryabov, E. V., Safronov, G. B., Seitova, D., Shaybonov, B. A., Shelepov, M. D., Shilkin, S. D., Shirokov, E. V., Šimkovic, F., Sirenko, A. E., Skurikhin, A. V., Solovjev, A. G., Sorokovikov, M. N., Štekl, I., Stromakov, A. P., Suvorova, O. V., Tabolenko, V. A., Ulzutuev, B. B., Yablokova, Y. V., Zaborov, D. N., Zavyalov, S. I., Erkenov, D. Y. Zvezdov A. K., Kosogorov, N. A., Kovalev, Y. A., Kovalev, Y. Y., Plavin, A. V., Popkov, A. V., Pushkarev, A. B., Semikoz, D. V., Sotnikova, Y. V., and Troitsky, S. V.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We report on the observation of a rare neutrino event detected by Baikal-GVD in April 2021. The event GVD210418CA is the highest-energy cascade observed by Baikal-GVD so far from the direction below the horizon. The estimated cascade energy is $224\pm75$~TeV. The evaluated signalness parameter of GVD210418CA is 97.1\% using an assumption of the E$^{-2.46}$ spectrum of astrophysical neutrinos. The arrival direction of GVD210418CA is near the position of the well-known radio blazar TXS~0506+056, with the angular distance being within a 90\% directional uncertainty region of the Baikal-GVD measurement. The event was followed by a radio flare observed by the RATAN-600 radio telescope, further strengthening the case for the neutrino-blazar association., Comment: 9 pages, 6 figures, Contribution to the 38th International Cosmic Rays Conference (ICRC2023). arXiv admin note: text overlap with arXiv:2210.01650

Published
2023

12. Search for directional associations between Baikal Gigaton Volume Detector neutrino-induced cascades and high-energy astrophysical sources

Author

Allakhverdyan, V. A., Avrorin, A. D., Avrorin, A. V., Aynutdinov, V. M., Bardacová, Z., Belolaptikov, I. A., Bondarev, E. A., Borina, I. V., Budnev, N. M., Chepurnov, A. S., Dik, V. Y., Domogatsky, G. V., Doroshenko, A. A., Dvornický, R., Dyachok, A. N., Dzhilkibaev, Zh. -A. M., Eckerová, E., Elzhov, T. V., Fajt, L., Gafarov, A. R., Golubkov, K. V., Gorshkov, N. S., Gress, T. I., Kebkal, K. G., Kharuk, I., Khramov, E. V., Kolbin, M. M., Konischev, K. V., Korobchenko, A. V., Koshechkin, A. P., Kozhin, V. A., Kruglov, M. V., Kulepov, V. F., Lemeshev, Y. E., Milenin, M. B., Mirgazov, R. R., Naumov, D. V., Nikolaev, A. S., Petukhov, D. P., Pliskovsky, E. N., Rozanov, M. I., Ryabov, E. V., Safronov, G. B., Seitova, D., Shaybonov, B. A., Shelepov, M. D., Shilkin, S. D., Shirokov, E. V., Šimkovic, F., Sirenko, A. E., Skurikhin, A. V., Solovjev, A. G., Sorokovikov, M. N., Štekl, I., Stromakov, A. P., Suvorova, O. V., Tabolenko, V. A., Ulzutuev, B. B., Yablokova, Y. V., Zaborov, D. N., Zavyalov, S. I., Zvezdov, D. Y., Kosogorov, N. A., Kovalev, Y. Y., Lipunova, G. V., Plavin, A. V., Semikoz, D. V., and Troitsky, S. V.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract

Baikal-GVD has recently published its first measurement of the diffuse astrophysical neutrino flux, performed using high-energy cascade-like events. We further explore the Baikal-GVD cascade dataset collected in 2018-2022, with the aim to identify possible associations between the Baikal-GVD neutrinos and known astrophysical sources. We leverage the relatively high angular resolution of the Baikal-GVD neutrino telescope (2-3 deg.), made possible by the use of liquid water as the detection medium, enabling the study of astrophysical point sources even with cascade events. We estimate the telescope's sensitivity in the cascade channel for high-energy astrophysical sources and refine our analysis prescriptions using Monte-Carlo simulations. We primarily focus on cascades with energies exceeding 100 TeV, which we employ to search for correlation with radio-bright blazars. Although the currently limited neutrino sample size provides no statistically significant effects, our analysis suggests a number of possible associations with both extragalactic and Galactic sources. Specifically, we present an analysis of an observed triplet of neutrino candidate events in the Galactic plane, focusing on its potential connection with certain Galactic sources, and discuss the coincidence of cascades with several bright and flaring blazars., Comment: 10 pages, 3 figures, accepted for publication in MNRAS

Published
2023
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13. Ontomathedu Ontology Enrichment Method

Author

Nevzorova, O. A. and Nikolaev, K. S.

Subjects
Computer Science - Artificial Intelligence
Abstract

Nowadays, distance learning technologies have become very popular. The recent pandemic has had a particularly strong impact on the development of distance education technologies. Kazan Federal University has a distance learning system based on LMS Moodle. This article describes the structure of the OntoMathEdu ecosystem aimed at improving the process of teaching school mathematics courses, and also provides a method for improving the OntoMathEdu ontology structure based on identifying new connections between contextually related concepts.

Published
2022

14. Self-Sustained Non-Equilibrium Co-existence of Fluid and Solid States in a Strongly Coupled Complex Plasma System

Author

Hariprasad, M. G, Bandyopadhyay, P., Nikolaev, V. S., Kolotinskii, D. A., Arumugam, S., Arora, G., Singh, S., Sen, A., and Timofeev, A. V.

Subjects
Physics - Plasma Physics
Abstract

A complex (dusty) plasma system is well known as a paradigmatic model for studying the kinetics of solid-liquid phase transitions in inactive condensed matter. At the same time, under certain conditions a complex plasma system can also display characteristics of an active medium with the micron-sized particles converting energy of the ambient environment into motility and thereby becoming active. We present a detailed analysis of the experimental complex plasmas system that shows evidence of a non-equilibrium stationary coexistence between a cold crystalline and a hot fluid state in the structure due to the conversion of plasma energy into the motion energy of microparticles in the central region of the system. The plasma mediated non-reciprocal interaction between the dust particles is the underlying mechanism for the enormous heating of the central subsystem, and it acts as a micro-scale energy source that keeps the central subsystem in the molten state. Accurate multiscale simulations of the system based on combined molecular dynamics and particle-in-cell approaches show that strong structural nonuniformity of the system under the action of electostatic trap makes development of instabilities a local process. We present both experimental tests conducted with a complex plasmas system in a DC glow discharge plasma and a detailed theoretical analysis., Comment: This paper contains 14 pages with eight figures

Published
2022

15. Conceptual design of the Spin Physics Detector

Author

Abazov, V. M., Abramov, V., Afanasyev, L. G., Akhunzyanov, R. R., Akindinov, A. V., Akopov, N., Alekseev, I. G., Aleshko, A. M., Alexakhin, V. Yu., Alexeev, G. D., Alexeev, M., Amoroso, A., Anikin, I. V., Andreev, V. F., Anosov, V. A., Arbuzov, A. B., Azorskiy, N. I., Baldin, A. A., Balandina, V. V., Baldina, E. G., Barabanov, M. Yu., Barsov, S. G., Baskov, V. A., Beloborodov, A. N., Belov, I. N., Belova, A. P., Belyaev, A. V., Berdnikov, A. Ya., Berdnikov, Ya. A., Berezhnoy, A. V., Bleko, V. V., Bobkov, A. V., Bogoslovsky, D. N., Boguslavsky, I. N., Boltushkin, E. V., Boos, E. E., Burtsev, V. E., Chen, Lei, Chepurnov, A. S., Chiosso, M., Chumakov, A., Dalkarov, O. D., Datta, A., Demikhov, E. I., Denisenko, I. I., Denisov, O. Yu., Duginov, V. N., Dunin, V. B., Dygnarowicz, K., Efremov, A. V., El-Kholy, R., Eliseev, D. A., Enik, T. L., Fedin, O. L., Feofilov, G. A., Filatov, Yu. N., Finger, M., Frolov, V. N., Galinski, G., Galoyan, A. S., Trapaga, C. E Garsia, Gavrishchuk, O. P., Gerasimov, S. G., Glonti, L., Goloskokov, S. V., Golovanov, G. A., Golubev, A. A., M., Golubykh S., V., Goncharov P., O., Grafov N., Y., Gribkov D., Gribovsky, A. S., Gridin, A. O., Grinyov, B. V., Gritsay, K. I., Gromov, S. A., Gromov, V. A., Gurchin, Yu. V., Gusakov, Yu. V., Guskov, A. V., Guzman, F., Haidenbauer, J., Havranek, M., Ivanov, A. V., Ivanov, N. Ya., Isupov, A. Yu., Jary, V., Jia, Shi-Hai, Jokovic, D., Kaplii, A., Karpishkov, A. V., Kasianova, E. A., Kekelidze, G. D., Khabarov, S. V., Kharusov, P. R., Khrenov, A. N., Kim, V. T., Kirichkov, N. V., Kirin, D. Yu., Kishchin, I., Klekotko, A., Klopot, Ya., Kluev, A., Kokoulina, E. S., Komarov, V. I., Kondratenko, A. M., Kondratenko, M. A., Konorov, I., Kopylov, Yu. A., Korjik, M. V., Korovkin, P. S., Korzenev, A. Yu., Kostukov, E. V., Kotzinian, A., Kovalenko, A. D., Kovalenko, V. N., A., Kozhin M., Kramarenko, V. A., Kruglov, V. N., Kubankin, A., Kubankin, Yu., Kuleshov, S., Kovtun, V. E., Kulikov, A. V., Kurbatov, V. S., Kurjata, R., Kutuzov, S. A., Kuznetsova, E. V., Ladygin, E. A., Ladygin, V. P., Larionova, D. M., Lednicky, D., Lednicky, R., Li, Pei-Yu, Li, Xiao-Mei, Lobko, A. S., Luschevskaya, E., L'vov, A. I., Lyashchenko, V. N., Lysan, V. M., Lyubovitskij, V., Maggiora, A., Maleev, V. P., Maltsev, A., Malykhina, T. V., Makankin, A. M., Makarenko, V. V., Maletic, D., Malkevich, D. B., Marcisovsky, M., Martovitsky, E. V., Marzec, J., Merkin, M. M., Meshcheriakov, G. V., Mitrankov, Yu. M., Mitrankova, M. M., Mitrofanov, E. O., Morozov, B., Moshkovsky, I. V., Movsisyan, A., Nagorniy, S. N., Nechaeva, P. Yu., Nefedov, M. A., Nefedov, Yu. A., Negodaev, M. A., Neue, G., Nikiforov, D. N., Nikitin, V. A., Nikolaev, A. S., Oleynik, D. A., Ososkov, G. A., Panzieri, D., Parsamyan, B., Parzhitsky, S. S., Pastuszak, G., Pavlov, V. V., Pavlova, A. A., Pelevanyuk, I. S., Perepelkin, E. E., Peshekhonov, D. V., Petrosyan, A. Sh., Piskun, A. A., Plotnikov, V. V., Podgainy, D. V., Polozov, P., Polyakova, R. V., Polyansky, V. V., Popov, V. V., Popule, J., Prochazka, I., Prokhorov, I. K., Reva, S. N., Reznikov, S. G., Rezvaya, E. P., Richard, J. -M., Rogachevsky, O. V., Romanov, V. M., Rudenko, A. I., Rumyantsev, M. A., Rusinov, V., Rybakov, N. A., Rychter, A., Rymbekova, A., Safonov, A. B., Salamatin, K. M., Saleev, V. A., Samartsev, A. G., Savenkov, A. A., Savic, M., Semak, A. A., Shaikovsky, V. N., Shavrin, A. A., Sheremeteva, A. I., Shimanskii, S. S., Shipilova, A. V., Shtejer, K., Shulyakovsky, R., Sinitsa, A. A., Skachkov, N. B., Skachkova, A. N., Slunecka, M., Sluneckova, V., Solin, A. A., Solin, A. V., Song, Jin-Xin, Sotnikov, V. V., Sun, Peng-Fei, Starikova, S. Yu., Stavinskiy, A. V., Streletskaya, E. A., Strikman, M., Strusik-Kotlozh, D., Suchkov, S. I., Sultanov, R. I., Sun, Hao, Svirida, D. N., Tarasov, O. G., Tarkovskyi, E. I., Temerbayev, A., Terekhin, A. A., V., Tereschenko V., R., Terkulov A., V., Teryaev O., V., Tishevsky A., V., Tkachenko A., Tokmenin, A. A. V. V., Tomasek, L., Tomasi-Gustafsson, E., Topchiev, N. P., Topilin, N. D., Topko, B. L., Tosello, F., Trifonov, A., Troyan., Yu. A., Trunov, N. O., Tsenov, R., Usenko, E. A., Uzhinsky, V. V., Uzikov, Yu. N., Valiev, F. F., Vasilieva, E. V., Vechernin, V. V., Verkheev, A. Yu., Vertogradov, L. S., Vertogradova, Yu. L., Vesenkov, V. A., Virius, M., Volchansky, N. I., Volkov, I. S., Volkov, P. V., Vorobiev, A., Vrba, V., Wang, Qian, Yudin, I. P., Zamora, J., Zamyatin, N. I., Zaremba, K., Zelenov, A. V., Zemlyanichkina, E. V., Zhang, Yun-Yu, Zhang, Jun-Wei, Zhao, Ming-Rui, Zhao, Qiang, Zhi, Yu, Zhemchugov, A. S., Zhevlakov, A., Zhigareva, N. M., Zhmurin, P. N., Zhukov, I. A., Zhuravlev., N. I, Ziembicki, M., Zinin, A. V., Zubarev, E. V., and Zuev, M. I.

Subjects
High Energy Physics - Experiment, Physics - Instrumentation and Detectors
Abstract

The Spin Physics Detector, a universal facility for studying the nucleon spin structure and other spin-related phenomena with polarized proton and deuteron beams, is proposed to be placed in one of the two interaction points of the NICA collider that is under construction at the Joint Institute for Nuclear Research (Dubna, Russia). At the heart of the project there is huge experience with polarized beams at JINR. The main objective of the proposed experiment is the comprehensive study of the unpolarized and polarized gluon content of the nucleon. Spin measurements at the Spin Physics Detector at the NICA collider have bright perspectives to make a unique contribution and challenge our understanding of the spin structure of the nucleon. In this document the Conceptual Design of the Spin Physics Detector is presented.

Published
2021

16. Kato expansion in quantum canonical perturbation theory

Author

Nikolaev, A. S.

Subjects
Quantum Physics, Mathematical Physics, Physics - Chemical Physics
Abstract

This work establishes a connection between canonical perturbation series in quantum mechanics and a Kato expansion for the resolvent of the Liouville superoperator. Our approach leads to an explicit expression for a generator of a block-diagonalizing Dyson's ordered exponential in arbitrary perturbation order. Unitary intertwining of perturbed and unperturbed averaging superprojectors allows for a description of ambiguities in the generator and block-diagonalized Hamiltonian. We compare the efficiency of the corresponding computational algorithm with the efficiencies of the Van Vleck and Magnus methods for high perturbative orders., Comment: 18 pages. Version 2: Additional discussion of the computational algorithms

Published
2015
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17. Orientation-dependent spontaneous emission rates of a two-level quantum emitter in any nanophotonic environment

Author

Vos, Willem L., Koenderink, A. Femius, and Nikolaev, Ivan S.

Subjects
Physics - Optics
Abstract

We study theoretically the rate of spontaneous emission of a two-level quantum emitter embedded in realistic systems: near a mirror, near a plasmonic sphere, or in a 3D photonic bandgap crystal. At constant frequency and position, we find striking (up to $10^{2}\times$) variations in emission rate by varying the orientation of the transition dipole moment. We present a general representation of rate versus orientation that only invokes symmetry of the Green function. The concomitant 3-dimensional geometric surfaces provide much insight in how preferred orientations for enhancement (or inhibition) depend on the emitter's frequency and location, and on optimal strategies to actively switch emission rates by controlling oriented dipoles., Comment: 5 figures

Published
2009
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18. Accurate calculation of the local density of optical states in inverse-opal photonic crystals

Author

Nikolaev, Ivan S., Vos, Willem L., and Koenderink, A. Femius

Subjects
Physics - Optics
Abstract

We have investigated the local density of optical states (LDOS) in titania and silicon inverse opals -- three-dimensional photonic crystals that have been realized experimentally. We used the H-field plane-wave expansion method to calculate the density of states and the projected local optical density of states, which are directly relevant for spontaneous emission dynamics and strong coupling. We present the first quantitative analysis of the frequency resolution and of the accuracy of the calculated local density of states. We have calculated the projected LDOS for many different emitter positions in inverse opals in order to supply a theoretical interpretation for recent emission experiments and as reference results for future experiments and theory by other workers. The results show that the LDOS in inverse opals strongly depends on the crystal lattice parameter as well as on the position and orientation of emitting dipoles., Comment: 11 figures

Published
2009
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19. Size-Dependence of the Wavefunction of Self-Assembled Quantum Dots

Author

Johansen, J., Stobbe, S., Nikolaev, I. S., Lund-Hansen, T., Kristensen, P. T., Hvam, J. M., Vos, W. L., and Lodahl, P.

Subjects
Condensed Matter - Other Condensed Matter
Abstract

The radiative and non-radiative decay rates of InAs quantum dots are measured by controlling the local density of optical states near an interface. From time-resolved measurements we extract the oscillator strength and the quantum efficiency and their dependence on emission energy. From our results and a theoretical model we determine the striking dependence of the overlap of the electron and hole wavefunctions on the quantum dot size. We conclude that the optical quality is best for large quantum dots, which is important in order to optimally tailor quantum dot emitters for, e.g., quantum electrodynamics experiments., Comment: 5 pages, 3 figures

Published
2007
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20. Statistical analysis of time-resolved emission from ensembles of semiconductor quantum dots: interpretation of exponential decay models

Author

van Driel, A. F., Nikolaev, I. S., Vergeer, P., Lodahl, P., Vanmaekelbergh, D., and Vos, W. L.

Subjects
Physics - Optics, Physics - Data Analysis, Statistics and Probability
Abstract

We present a statistical analysis of time-resolved spontaneous emission decay curves from ensembles of emitters, such as semiconductor quantum dots, with the aim to interpret ubiquitous non-single-exponential decay. Contrary to what is widely assumed, the density of excited emitters and the intensity in an emission decay curve are not proportional, but the density is a time-integral of the intensity. The integral relation is crucial to correctly interpret non-single-exponential decay. We derive the proper normalization for both a discrete, and a continuous distribution of rates, where every decay component is multiplied with its radiative decay rate. A central result of our paper is the derivation of the emission decay curve in case that both radiative and non-radiative decays are independently distributed. In this case, the well-known emission quantum efficiency can not be expressed by a single number anymore, but it is also distributed. We derive a practical description of non-single-exponential emission decay curves in terms of a single distribution of decay rates; the resulting distribution is identified as the distribution of total decay rates weighted with the radiative rates. We apply our analysis to recent examples of colloidal quantum dot emission in suspensions and in photonic crystals, and we find that this important class of emitters is well described by a log-normal distribution of decay rates with a narrow and a broad distribution, respectively. Finally, we briefly discuss the Kohlrausch stretched-exponential model, and find that its normalization is ill-defined for emitters with a realistic quantum efficiency of less than 100 %., Comment: 18 pages, 5 figures; revised order of presentation

Published
2006
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21. Strongly nonexponential time-resolved fluorescence of quantum-dot ensembles in three-dimensional photonic crystals

Author

Nikolaev, Ivan S., Lodahl, Peter, van Driel, A. Floris, Koenderink, A. Femius, and Vos, Willem L.

Subjects
Physics - Optics
Abstract

We observe experimentally that ensembles of quantum dots in three-dimensional (3D) photonic crystals reveal strongly nonexponential time-resolved emission. These complex emission decay curves are analyzed with a continuous distribution of decay rates. The log-normal distribution describes the decays well for all studied lattice parameters. The distribution width is identified with variations of the radiative emission rates of quantum dots with various positions and dipole orientations in the unit cell. We find a striking sixfold change of the width of the distribution by varying the lattice parameter. This interpretation qualitatively agrees with the calculations of the 3D projected local density of states. We therefore conclude that fluorescence decay of ensembles of quantum dots is highly nonexponential to an extent that is controlled by photonic crystals., Comment: - changed content - 5 pages with 4 figures

Published
2005
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22. Quantitative analysis of directional spontaneous emission spectra from light sources in photonic crystals

Author

Nikolaev, Ivan S., Lodahl, Peter, and Vos, Willem L.

Subjects
Physics - Popular Physics
Abstract

We have performed angle-resolved measurements of spontaneous-emission spectra from laser dyes and quantum dots in opal and inverse opal photonic crystals. Pronounced directional dependencies of the emission spectra are observed: angular ranges of strongly reduced emission adjoin with angular ranges of enhanced emission. It appears that emission from embedded light sources is affected both by the periodicity and by the structural imperfections of the crystals: the photons are Bragg diffracted by lattice planes and scattered by unavoidable structural disorder. Using a model comprising diffuse light transport and photonic band structure, we quantitatively explain the directional emission spectra. This provides detailed understanding of the transport of spontaneously emitted light in real photonic crystals, which is essential in the interpretation of quantum-optics in photonic band-gap crystals and for applications wherein directional emission and total emission power are controlled., Comment: 10 pages, 10 figures, corrected pdf, inserted new reference

Published
2004
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23. Cosmic ray acceleration by stellar wind. Simulation for heliosphere

Author

Petukhov, S. I, Turpanov, A. A, and Nikolaev, V. S

Subjects
Solar Physics
Abstract

The solar wind deceleration by the interstellar medium may result in the existence of the solar wind terminal shock. In this case a certain fraction of thermal particles after being heated at the shock would obtain enough energy to be injected to the regular acceleration process. An analytical solution for the spectrum in the frame of a simplified model that includes particle acceleration at the shock front and adiabatic cooling inside the stellar wind cavity has been derived. It is shown that the acceleration of the solar wind particles at the solar wind terminal shock is capable of providing the total flux, spectrum and radial gradients of the low-energy protons close to one observed in the interplanetary space.

Published
1985

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