We have analyzed the neutrino events recoded in the deep-water neutrino experiment NT200 in Lake Baikal in five years of observations toward dark dwarf spheroidal galaxies (dSphs) in the southern ...hemisphere and the Large Magellanic Cloud (LMC). This analysis completes the series of works based on NT200 data in the search for a dark matter annihilation signal in astrophysical objects. We have found no significant excess in the number of observed events relative to the expected background from atmospheric neutrinos in all tested directions, in 22 dSphs and the LMC. For a sample of five selected dwarf galaxies we have performed a joint analysis of the data by the maximum likelihood method. We have obtained a correspondence of the observational data to the null hypothesis about the presence of only background events and established 90% confidence-level upper limits for the annihilation cross sections of dark matter particles with a mass from 30 GeV to 10 TeV in several annihilation channels both in the joint analysis of the selected sample of galaxies and in the analysis toward the LMC. The strongest constraints at a level of 7 × 10
–21
cm
3
s
–1
have been obtained for the direction toward the LMC in the channel of annihilation into a pair of neutrinos.
We have analyzed a data set taken over 2.76years live time with the Baikal neutrino telescope NT200. The goal of the analysis is to search for neutrinos from dark matter annihilation in the center of ...the Sun. Apart from the conventional annihilation channels bb¯, W+W- and τ+τ- we consider also the annihilation of dark matter particles into monochromatic neutrinos. From the absence of any excess of events from the direction of the Sun over the expected background, we derive 90% upper limits on the fluxes of muons and muon neutrinos from the Sun, as well as on the elastic cross sections of dark matter scattering on protons.
Abstract
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 ±1 h and ±12 h does not indicate statistically significant excess of the measured events over the expected number of background events. Upper limits on the neutrino fluence will be presented for each alert.
Baikal-GVD Avrorin, A.D.; Avrorin, A.V.; Aynutdinov, V.M. ...
EPJ Web of Conferences,
01/2017, Letnik:
136
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
We present the status of the Gigaton Volume Detector in Lake Baikal (Baikal-GVD) designed for the detection of high energy neutrinos of astrophysical origin. The telescope consists of functionally ...independent clusters, sub-arrays of optical modules (OMs), which are connected to shore by individual electro-optical cables. During 2015 the GVD demonstration cluster, comprising 192 OMs, has been successfully operated in Lake Baikal. In 2016 this array was upgraded to baseline configuration of GVD cluster with 288 OMs arranged on eight vertical strings. Thus the instrumented water volume has been increased up to about 5.9 Mtons. The array was commissioned in early April 2016 and takes data since then. We describe the configuration and design of the 2016 array. Preliminary results obtained with data recorded in 2015 are also discussed.
Abstract
The Baikal-GVD is a neutrino telescope situated in the deepest freshwater lake in the world — Lake Baikal. The design of the Baikal-GVD trigger system allows also to study the ambient light ...of the lake. The analysis of the optical light activity of Baikal water, particularly, time and spatial variations of the luminescence activity for data collected in years 2018, 2019, and 2020 is presented. For the first time we observed highly luminescent layer moving upwards with maximal speed of 28 m/day in January 2021.
Baikal-GVD is a cubic-kilometer scale neutrino telescope, which is currently under construction in Lake Baikal. Baikal-GVD is an array of optical modules arranged in clusters. The first cluster of ...the array has been deployed and commissioned in April 2015. To date, Baikal-GVD consists of 3 clusters with 864 optical modules. One of the vital conditions for optimal energy, position and direction reconstruction of the detected particles is the time calibration of the detector. In this article, we describe calibration equipment and methods used in Baikal-GVD and demonstrate the accuracy of the calibration procedures.
Abstract
The first stage of the construction of the Baikal-GVD deep underwater neutrino telescope is planned to be completed in 2024. For the second stage of the detector deployment, a data ...acquisition system based on fiber-optic technologies has been proposed, which will allow for increased data throughput and more flexible trigger conditions. A dedicated test facility has been built and deployed at the Baikal-GVD site to test the new technological solutions. We present the principles of operation and results of tests of the new data acquisition system.
The second-stage neutrino telescope BAIKAL-GVD in Lake Baikal will be a research infrastructure aimed mainly at studying astrophysical neutrino fluxes by recording the Cherenkov radiation of the ...secondary muons and showers generated in neutrino interactions. The prototyping/early construction phase of the BAIKAL-GVD project which is directed towards deployment and operation of the first demonstration cluster has been started in April 2011. An important step on realization of the GVD project was made in 2014 by the deployment of the second stage of the demonstration cluster which contains 112 OMs arranged on five strings, as well as equipment of an acoustic positioning system and instrumentation string with an array calibration and environment monitoring equipment. Deployment of the demonstration cluster will be completed in 2015.
Baikal-GVD is a cubic kilometer-scale neutrino telescope currently under construction in Lake Baikal. The detector’s components are mobile and may drift from their initial coordinates or change their ...spatial orientation. This introduces a reconstruction error, particularly a timing error for PMT hits. This problem is mitigated by a combination of a hydroacoustic positioning system and per-component acceleration and orientation sensors. Under regular conditions, the average positioning accuracy for a GVD component is estimated to be less than 13 cm.
Status of the Baikal-GVD Neutrino Telescope Avrorin, A.D.; Avrorin, A.V.; Aynutdinov, V.M. ...
EPJ Web of Conferences,
2019, Letnik:
207
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
Currently in Lake Baikal a new-generation neutrino telescope is being deployed: Baikal-GVD, a deep underwater Cherenkov detector on the cubic-kilometer scale. This paper presents the status of the ...detector implementation and the first physical results obtained with the existing configuration.
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