6 pages, 4 figures. Talk presented at the 40th International Conference on High Energy Physics, 28 July - 6 August 2020, Prague, Czech Republic (Virtual Conference). Proceeding: PoS(ICHEP2020)606
Baikal-GVD is a cubic-kilometer scale deep-underwater neutrino detector being constructed in Lake Baikal. It is designed to detect neutrinos from $\sim$100 GeV to multi-PeV energies and beyond. Detector deployment began in Spring 2015. Since April 2020 the detector includes seven 8-string clusters carrying in total 2016 optical modules located at depths from 750 to 1275 meters. By the end of the first phase of detector construction in 2024 it is planned to deploy 15 clusters, reaching the effective volume for high-energy cascade detection of 0.75 km$^3$. The design and status of the Baikal-GVD detector and first results of data analysis are presented in this report.
Neutrino astronomy offers a novel view of the non-thermal Universe and is complementary to other astronomical disciplines. The field has seen rapid progress in recent years, including the first detection of astrophysical neutrinos in the TeV-PeV energy range by IceCube and the first identified extragalactic neutrino source (TXS 0506+056). Further discoveries are aimed for with new cubic-kilometer telescopes in the Northern Hemisphere: Baikal-GVD, in Lake Baikal, and KM3NeT-ARCA, in the Mediterranean sea. The construction of Baikal-GVD proceeds as planned; the detector currently includes over 2…
Baikal-GVD is a km$^3$-scale neutrino telescope being constructed in Lake Baikal. Muon and partially tau (anti)neutrino interactions near the detector through the W$^{\pm}$-boson exchange are accompanied by muon tracks. Reconstructed direction of the track is arguably the most precise probe of the neutrino direction attainable in Cerenkov neutrino telescopes. Muon reconstruction techniques adopted by Baikal-GVD are discussed in the present report. Performance of the muon reconstruction is studied using realistic Monte Carlo simulation of the detector. The algorithms are applied to real data fr…
The Baikal Gigaton Volume Detector (Baikal-GVD) is a km$^3$-scale neutrino detector currently under construction in Lake Baikal, Russia. The detector currently consists of 2304 optical modules arranged on 64 vertical strings. Further extension of the array is planned for March 2022. The data from the partially complete array have been analyzed using a $χ^2$-based track reconstruction algorithm. After suppression of the downward-going atmospheric muon background, a flux of upward-going neutrino events is observed, dominated by the atmospheric neutrinos. The observed flux is in good agreement wi…
Currently in Lake Baikal, a new generation neutrino telescope is being deployed: the deep underwater Cherenkov detector of a cubic-kilometer scale Baikal-GVD. Completion of the first stage of the telescope construction is planned for 2021 with the implementation of 9 clusters. Each cluster is a completely independent unit in all the aspects: triggering, calibration, data transfer, etc. A high-energy particle might leave its trace in more than a single cluster. To be able to merge events caused by such a particle in more clusters, the appropriate inter-cluster time synchronization is vital.
Towards Baikal-Top: Feasibility study of an onshore detector system for the joint registration of EAS with Baikal-GVD
Budker Institute of Nuclear Physics SB RAS（布杰尔核物理研究所）；Novosibirsk State University（新西伯利亚国立大学）；Institute for Nuclear Research of the Russian Academy of Sciences（俄罗斯科学院核物理研究所）
Baikal-GVD is a next generation, kilometer-scale neutrino telescope currently under construction in Lake Baikal. GVD is formed by multi-megaton sub-arrays (clusters) and is designed for the detection of astrophysical neutrino fluxes at energies from a few TeV up to 100 PeV. The design of the Baikal-GVD allows one to search for astrophysical neutrinos with flux values measured by IceCube already at early phases of the array construction. We present here preliminary results of the search for high-energy neutrinos via the cascade mode with the Baikal-GVD neutrino telescope.
We present data on the luminescence of the Baikal water medium collected with the Baikal-GVD neutrino telescope. This three-dimensional array of light sensors allows the observation of time and spatial variations of the ambient light field. We report on observation of an increase of luminescence activity in 2016 and 2018. On the contrary, we observed practically constant optical noise in 2017. An agreement has been found between two independent optical noise data sets. These are data collected with online monitoring system and the trigger system of the cluster.
The Prototyping phase of the BAIKAL-GVD project has been started in April 2011 with the deployment of a three string engineering array which comprises all basic elements and systems of the Gigaton Volume Detector (GVD) in Lake Baikal. In April 2012 the version of engineering array which comprises the first full-scale string of the GVD demonstration cluster has been deployed and operated during 2012. The first stage of the GVD demonstration cluster which consists of three strings is deployed in April 2013. We review the Prototyping phase of the BAIKAL-GVD project and describe the configuration …
Rejecting noise in Baikal-GVD data with neural networks
Institute for Nuclear Research of the Russian Academy of Sciences（俄罗斯科学院核研究所）；Moscow Institute of Physics and Technology（莫斯科物理技术学院）；Novosibirsk State University（新西伯利亚国立大学）；Joint Institute for Nuclear Research（联合核研究所）
The main purpose of the Baikal-GVD Data Quality Monitoring (DQM) system is to monitor the status of the detector and collected data. The system estimates quality of the recorded signals and performs the data validation. The DQM system is integrated with the Baikal-GVD's unified software framework ("BARS") and operates in quasi-online manner. This allows us to react promptly and effectively to the changes in the telescope conditions.
Baikal-GVD is a neutrino telescope currently under construction in Lake Baikal. GVD is formed by multi-meganton subarrays (clusters). The design of Baikal-GVD allows one to search for astrophysical neutrinos already at early phases of the array construction. We present here preliminary results of a search for high-energy neutrinos with GVD in 2019-2020.
In April 2019, the Baikal-GVD collaboration finished the installation of the fourth and fifth clusters of the neutrino telescope Baikal-GVD. Momentarily, 1440 Optical Modules (OM) are installed in the largest and deepest freshwater lake in the world, Lake Baikal, instrumenting 0.25 cubic km of sensitive volume. The Baikal-GVD is thus the largest neutrino telescope on the Northern Hemisphere. The first phase of the detector construction is going to be finished in 2021 with 9 clusters, 2592 OMs in total, however the already installed clusters are stand-alone units which are independently operati…
Multi-messenger astronomy is a powerful tool to study the physical processes driving the non-thermal Universe. A combination of observations in cosmic rays, neutrinos, photons of all wavelengths and gravitational waves is expected. The alert system of the Baikal-GVD detector under construction will allow for a fast, on-line reconstruction of neutrino events recorded by the Baikal-GVD telescope and - if predefined conditions are satisfied - for the formation of an alert message to other communities. The preliminary results of searches for high-energy neutrinos in coincidence with GW170817/GRB17…
We present data on the Baikal water luminescence collected with the Baikal-GVD neutrino telescope. This three-dimensional array of photo-sensors allows the observation of time and spatial variations of the ambient light field. We report on annual increase of luminescence activity in years 2018-2020. We observed a unique event of a highly luminescent layer propagating upwards with a maximum speed of 28 m/day for the first time.
The Baikal Gigaton Volume Detector (Baikal-GVD) is a km$^3$-scale neutrino detector currently under construction in Lake Baikal, Russia. The detector consists of several thousand optical sensors arranged on vertical strings, with 36 sensors per string. The strings are grouped into clusters of 8 strings each. Each cluster can operate as a stand-alone neutrino detector. The detector layout is optimized for the measurement of astrophysical neutrinos with energies of $\sim$ 100 TeV and above. Events resulting from charged current interactions of muon (anti-)neutrinos will have a track-like topolog…
We analyse sensitivity of the gigaton volume telescope Baikal-GVD for detection of neutrino signal from dark matter annihilations or decays in the Galactic Center. Expected bounds on dark matter annihilation cross section and its lifetime are found for several annihilation/decay channels.
First constraints on point-like astrophysical sources using Baikal-GVD muon neutrino events
Joint Institute for Nuclear Research（苏联联合核子研究所）；Institute for Nuclear Research, Russian Academy of Sciences（俄罗斯科学院核物理研究所）；Comenius University（布拉迪斯拉发康斯坦丁神学家大学）；Czech Technical University in Prague（捷克理工大学）；Irkutsk State University（伊尔库茨克国立大学）；Skobeltsyn Institute of Nuclear Physics MSU（莫斯科国立大学索别利岑核物理研究所）；Institute of Nuclear Physics of the Ministry of Energy of the Republic of Kazakhstan（哈萨克斯坦共和国能源部核物理研究所）；National Research Nuclear University MEPHI（莫斯科工程物理国家研究大学）
The high-energy muon neutrino events of the IceCube telescope, that are triggered as neutrino alerts in one of two probability ranks of astrophysical origin, "gold" and "bronze", have been followed up by the Baikal-GVD in a fast quasi-online mode since September 2020. Search for correlations between alerts and GVD events reconstructed in two modes, muon-track and cascades (electromagnetic or hadronic showers), for the time windows $ \pm $ 1 h and $ \pm $ 12 h does not indicate statistically significant excess of the measured events over the expected number of background events. Upper limits on…
The Baikal-GVD deep underwater neutrino experiment participates in the international multi-messenger program on discovering the astrophysical sources of high energy fluxes of cosmic particles, while being at the stage of deployment with a gradual increase of its effective volume to the scale of a cubic kilometer. In April 2021 the effective volume of the detector has been reached 0.4 km3 for cascade events with energy above 100 TeV generated by neutrino interactions in Lake Baikal. The alarm system in real-time monitoring of the celestial sphere was launched at the beginning of 2021, that allo…
The quality of the incoming experimental data has a significant importance for both analysis and running the experiment. The main point of the Baikal-GVD DQM system is to monitor the status of the detector and obtained data on the run-by-run based analysis. It should be fast enough to be able to provide analysis results to detector shifter and for participation in the global multi-messaging system.
Joint Institute for Nuclear Research（联合核研究所）；Institute for Nuclear Research, Russian Academy of Sciences（俄罗斯科学院核物理研究所）；Comenius University（布拉迪斯拉发康斯坦丁神甫大学）；Czech Technical University in Prague（捷克理工大学）；Irkutsk State University（伊尔库茨克国立大学）；Skobeltsyn Institute of Nuclear Physics MSU（莫斯科国立大学斯科别尔钦核物理研究所）；Institute of Nuclear Physics of the Ministry of Energy of the Republic of Kazakhstan（哈萨克斯坦共和国能源部核物理研究所）
The Advanced LIGO and Advanced Virgo observatories recently discovered gravitational waves from a binary neutron star inspiral. A short gamma-ray burst (GRB) that followed the merger of this binary was also recorded by Fermi-GBM and INTEGRAL, indicating particle acceleration by the source. The precise location of the event was determined by optical detections of emission following the merger. We searched for high-energy neutrinos from the merger in the TeV - 100 PeV energy range using Baikal-GVD. No neutrinos directionally coincident with the source were detected within $\pm$500 s around the m…
The progress in the construction and operation of the Baikal Gigaton Volume Detector in Lake Baikal is reported. The detector is designed for search for high energy neutrinos whose sources are not yet reliably identified. It currently includes 2304 optical modules arranged on 64 strings, providing an effective volume of 0.4 km3 for cascades with energy above 100 TeV. We review the scientific case for Baikal-GVD, the construction plan, and first results from the partially built experiment, which is currently the largest neutrino telescope in the Northern Hemisphere and still growing up.
We report theoretical and experimental results of on-going feasibility studies to detect cosmic neutrinos acoustically in Lake Baikal. In order to examine ambient noise conditions and to develop respective pulse detection techniques a prototype device was created. The device is operating at a depth of 150 m at the site of the Baikal Neutrino Telescope and is capable to detect and classify acoustic signals with different shapes, as well as signals from neutrino-induced showers.
With the identification of a diffuse flux of astrophysical ("cosmic") neutrinos in the TeV-PeV energy range, IceCube has opened a new window to the Universe. However, the corresponding cosmic landscape is still uncharted: so far, the observed flux does not show any clear association with known source classes. In the present talk, I sketch the way from Baikal-NT200 to IceCube and summarize IceCube's recent astrophysics results. Finally, I describe the present projects to build even larger detectors: GVD in Lake Baikal, KM3NeT in the Mediterranean Sea and IceCube-Gen2 at the South Pole. These de…
This paper reviews the status of the search for high-energy neutrinos from astrophysical sources. Results from large neutrino telescopes in water (Antares, Baikal) and ice (IceCube) are discussed as well as observations from the surface with Auger and from high altitude with ANITA. Comments on IceTop, the surface component of IceCube are also included.
The new EAS Cherenkov array Tunka-133 with about 1 km**2 geometric acceptance area is installed in the Tunka Valley (50 km from Lake Baikal). The array willpermit a detailed study of cosmic ray energy spectrum and mass composition in the energy range of 10**15 - 10**18 eV with uniform method. The array consistsof 19 clusters, each composed of 7 optical detectors with 20 cm PMTs. Since November 2008, the first 12 clusters are in operation, commissioning of the whole array is planned for September 2009 (At the time of submission of this paperto electronic arXiv(February 2010) the completed Tunka…
Tunka-Rex is the radio extension of Tunka-133 located in Siberia close to Lake Baikal. The latter is a photomultiplier array registering air-Cherenkov light from air showers induced by cosmic-ray particles with initial energies of approximately $10^{16}$ to $10^{18}$ eV. Tunka-Rex extends this detector with 25 antennas spread over an area of 1 km$^2$. It is triggered externally by Tunka-133, and detects the radio emission of the same air showers. The combination of an air-Cherenkov and a radio detector provides a facility for hybrid measurements and cross-calibration between the two techniques…
Tunka-Rex is a new radio antenna array which extends the Tunka experiment in Siberia close to lake Baikal. It consists of 20 antennas on an area of 1 km^2 which measure the radio emission of high-energy air showers. Tunka-Rex is triggered by the photomultiplier array of Tunka measuring air-Cherenkov light of air showers in the energy range from about 10 PeV to 1 EeV. This configuration allows for the worldwide first hybrid measurements of the radio and air-Cherenkov signal for the same events: an ideal situation to perform a cross-calibration between both methods. Consequently, the main goal o…
