We reanalyze dataset collected during 1998-2003 years by the low energy threshold (10 GeV) neutrino telescope NT200 in the lake Baikal in searches for neutrino signal from dark matter annihilations ...near the center of the Milky Way. Two different approaches are used in the present analysis: counting events in the cones around the direction towards the Galactic Center and the maximum likelihood method. We assume that the dark matter particles annihilate dominantly over one of the annihilation channels \(b\bar{b}\), \(W^+W^-\), \(\tau^+\tau^-\), \(\mu^+\mu^-\) or \(\nu\bar{\nu}\). No significant excess of events towards the Galactic Center over expected background of atmospheric origin is found and we derive 90% CL upper limits on the annihilation cross section of dark matter.
Baikal-GVD: first cluster Dubna Avrorin, A D; Avrorin, A V; Aynutdinov, V M ...
arXiv (Cornell University),
11/2015
Paper, Journal Article
Odprti dostop
In April 2015 the demonstration cluster "Dubna" was deployed and started to take data in Lake Baikal. This array is the first cluster of the cubic kilometer scale Gigaton Volume Detector ...(Baikal-GVD), which is constructed in Lake Baikal. In this contribution we will review the design and status of the array.
The optical module of Baikal-GVD Avrorin, A. D.; Avrorin, A. V.; Aynutdinov, V. M. ...
Physics of particles and nuclei letters,
11/2016, Letnik:
13, Številka:
6
Journal Article
Recenzirano
Odprti dostop
In April 2015, the first cluster of Baikal-GVD was deployed in Lake Baikal and put into operation. It comprises eight strings. Each string consists of 24 optical modules. An optical module is a ...detection element of Baikal-GVD; it includes a Hamamatsu R7081-100 photomultiplier tube with a high quantum sensitivity. We describe the design of the optical module, the front-end electronics, and the laboratory characterization and calibration.
We review the status of high-energy acoustic neutrino detection activities in Lake Baikal. The Baikal collaboration constructed a hydro-acoustic device which may be regarded as a prototype subunit ...for a future underwater acoustic neutrino telescope. The device is capable of common operation with the Baikal neutrino telescope NT200+, and is operating at a depth of about 150
m on the “NT200+ instrumentation string”. Our measurements show that the integral noise power in the frequency band 20–40
kHz can reach levels as low as about 1
mPa, i.e. one of the lowest noise levels measured at the currently considered acoustic neutrino sites. At the same time, short acoustic pulses with different amplitudes and shapes have been observed. Low sound absorption in Baikal freshwater and absence of strong acoustic noise sources do motivate further activities towards a large-scale acoustic neutrino detector in Lake Baikal.
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.
The NT1000 deep-water neutrino telescope with an effective volume of ∼2 km
3
is currently being developed at Lake Baikal by the BAIKAL collaboration. The telescope will be composed of functionally ...independent setups—clusters of strings of optical modules based on photomultiplier tubes (with eight strings in each cluster). Since 2011, field tests of the basic elements and systems of the future telescope included in autonomous measuring complexes—prototypes of the NT1000 cluster—have been performed at Lake Baikal. The basic elements and the layout of one of the currently considered versions of the acoustic positioning system for the NT1000 telescope are described, and results of tests of the system prototype included as a component in the experimental cluster of the year 2012 are presented.
We have analyzed a data set taken over 2.76 years 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 \(b\bar{b}\), \(W^+W^-\) and \(\tau^+\tau^-\) 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.
We review the status of the Baikal Neutrino Experiment. The Neutrino Telescope NT200 is operating in Lake Baikal since 1998 and has been upgraded to the 10
Mton detector
NT
200
+
in 2005. We present ...selected results concerning astroparticle physics as well as results of environmental studies. We describe the strategy of creating a Gigaton (km
3) scale neutrino detector at Lake Baikal. First steps of activities towards a km
3 Baikal neutrino telescope, including the development of acoustic high-energy neutrino detection methods are discussed.
We present the results of our search for neutrino events coinciding in time and direction with gamma-ray bursts (GRBs) with the Baikal underwater neutrino telescope NT200. No events confirming a ...neutrino accompaniment of GRBs have been detected. Model-independent limits (Greens function) on the neutrino flux from GRBs have been obtained. For the Waxman-Bahcall neutrino spectrum, the limit on the neutrino flux from a GRB has been found to be
E
ν
2
Φ
ν
⩽ 1.1 × 10
−6
GeV cm
−2
s
−1
sr
−1
.
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 and design of the 2013 engineering array.
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