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[show abstract]
[hide abstract]
ABSTRACT: According to the model of rotating collapsar, the gravitational stellar collapse occurs in two stages. During the first stage,
electron neutrinos with average energies from 30 to 40 MeV, formed in the neutronization reaction (p + e
− → n + νe), are mainly emitted. Previously iron was considered as a target for detecting neutrinos of such energies. It is shown in
this study that addition of kitchen salt to the structure of existing detectors can both significantly improve the neutrino
type identification and increase the active mass of existing detectors.
Bulletin of the Russian Academy of Sciences Physics 04/2012; 73(5):652-654.
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N. Yu. Agafonova, V. V. Boyarkin,
V. L. Dadykin,
E. A. Dobrynina,
R. I. Enikeev,
G. T. Zatsepin,
A. S. Malgin,
O. G. Ryazhskaya,
V. G. Ryasny,
I. R. Shakiryanova,
V. F. Yakushev,
the LVD Collaboration
[show abstract]
[hide abstract]
ABSTRACT: The Russian-Italian Large Volume Detector (LVD) is located at the Gran Sasso underground laboratory at a depth of 3300 m w.e.
To study the seasonal variations of the penetrating component of cosmic rays, the data on cosmic ray muons detected in 2001–2008
was analyzed, along with those associated with neutrons produced by muons since April 2003. One-year periodic variations of
muons and neutrons produced by them were found. The maximum intensity is observed in July, in accord with theoretical concepts.
Bulletin of the Russian Academy of Sciences Physics 04/2012; 75(3):427-430.
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N. Yu. Agafonova, V. V. Boyarkin,
V. L. Dadykin,
E. A. Dobrynina,
R. I. Enikeev,
A. S. Malgin,
O. G. Ryazhskaya,
V. G. Ryasny,
I. R. Shakiryanova,
V. F. Yakushev,
G. T. Zatsepin,
the LVD Collaboration
[show abstract]
[hide abstract]
ABSTRACT: The large geometric factor and good spatial resolution of the Large Volume Detector (LVD) ensures statistically significant
and highly accurate measurements of muon trajectories and determination of the multiplicity of muon groups. The developed
algorithm allows us to reconstruct 2 × 106 muon events (single muons and muon groups). Characteristics of muon groups are obtained and the specific yield of neutrons
produced by single muons, muon groups, and showers is determined.
Bulletin of the Russian Academy of Sciences Physics 04/2012; 75(3):408-410.
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N. Yu. Agafonova, V. V. Boyarkin,
V. L. Dadykin,
E. A. Dobrynina,
R. I. Enikeev,
G. T. Zatsepin,
A. S. Malgin,
O. G. Ryazhskaya,
V. G. Ryasny,
I. R. Shakiryanova,
V. F. Yakushev,
the LVD Collaboration
[show abstract]
[hide abstract]
ABSTRACT: The main goal of the Large Volume Detector (LVD) is to search for neutrino burst from gravitational stellar collapses in our
Galaxy. The apparatus is shown to be able to register stellar collapse even if there is none of the antineutrino emission
specific to the standard scenario. The data from more than nine years of detector operation have been processed, and no candidate
events for neutrino bursts have been detected. This implies the existence of an experimental limit to the galactic stellar
collapse rate in those cases where collapse is not accompanied by electron antineutrino emission: less than one event per
4.1 yr at the 90% confidence level.
Bulletin of the Russian Academy of Sciences Physics 04/2012; 75(3):416-418.
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[show abstract]
[hide abstract]
ABSTRACT: The basic task of the Large Volume Detector LVD situated at the underground Gran Sasso National Laboratory (Italy) is the
search for neutrino bursts from gravitational stellar collapses in our Galaxy. At present, the algorithm for determining neutrino
bursts has been developed. It is based on the identification of event clusters in fixed time intervals, special attention
is paid not only to the inverse β decay reaction which has a characteristic signature, but also to the neutrino-iron interaction.
The data for of 3.5 years of LVD operation have been processed. No candidates for neutrino bursts are found.
Bulletin of the Russian Academy of Sciences Physics 04/2012; 73(5):649-651.
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[show abstract]
[hide abstract]
ABSTRACT: Collection of light in a counter with mirror reflection from relief (nonflat) surfaces and with a high transparency of the liquid scintillator was investigated. Based on results of measurements and simulation of light collection, the dependence of light collection coefficient K on the relief of reflecting surfaces and the scintillator transparency was obtained using the Monte Carlo method. The light collection coefficient was K=(30.9+/- 1.1)× 10^(–3), and the resolution of the distribution function for the K value over the counter volume was η ≈ 12%
Instruments and Experimental Techniques 01/2010; 53(1):45-49. · 0.36 Impact Factor
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N Yu Agafanova, V V Boyarkin,
V L Dadykin,
E A Dobrynina,
R I Enikeev,
A S Malgin,
O G Ryazhskaya,
V G Ryasny,
V F Yakushev,
N M Sobolevsky,
V V Kuznetsov
[show abstract]
[hide abstract]
ABSTRACT: The energy spectrum of neutrons produced by cosmic ray muons in the underground detector LVD (3650 m.w.e.) is obtained for the energy range of 30–450 MeV. The spectrum is derived using the energy release spectrum of neutron interaction products in 1.5 m 3 scintillation counters.
Bulletin of the Russian Academy of Sciences Physics 01/2009; 73(73-5):1062-8738.
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N Yu Agafonova, V.V. Boyarkin,
V L Dadykin,
E E Dobrynina,
R I Enikeev,
V. V. Kuznetsov,
A. S. Malgin,
O. G. Ryazhskaya,
V. G. Ryasny,
V. F. Yakushev,
N. M. Sobolevsky,
the LVD Collaboration
[show abstract]
[hide abstract]
ABSTRACT: The energy spectrum of neutrons produced by cosmic ray muons in the underground detector LVD (3650 m.w.e.) is obtained for the energy range of 30–450 MeV. The spectrum is derived using the energy release spectrum of neutron interaction products in 1.5 m^3 scintillation counters.
Bulletin of the Russian Academy of Sciences Physics 01/2009; 73(5):628–629.
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N. Yu. Agafonova,
M Aglietta,
P. Antonioli,
G Bari,
A. Bonardi, V. V. Boyarkin,
G Bruno,
W. Fulgione,
P Galeotti,
M. Garbini, [......],
V. G. Ryasny,
O. G. Ryazhskaya,
O. Saavedra,
G Sartorelli,
M. Selvi,
C. Vigorito,
L Votano,
V. F. Yakushev,
G. T. Zatsepin,
A. Zichichi
[show abstract]
[hide abstract]
ABSTRACT: The CERN Neutrino to Gran Sasso (CNGS) project aims to produce a high energy, wide band $\nu_{\mu}$ beam at CERN and send it toward the INFN Gran Sasso National Laboratory (LNGS), 732 km away. Its main goal is the observation of the $\nu_{\tau}$ appearance, through neutrino flavour oscillation. The beam started its operation in August 2006 for about 12 days: a total amount of $7.6~10^{17}$ protons were delivered to the target. The LVD detector, installed in hall A of the LNGS and mainly dedicated to the study of supernova neutrinos, was fully operating during the whole CNGS running time. A total number of 569 events were detected in coincidence with the beam spill time. This is in good agreement with the expected number of events from Montecarlo simulations.
11/2007;
-
N. Yu. Agafonova,
M Aglietta,
P. Antonioli,
G Bari,
A. Bonardi, V. V. Boyarkin,
G Bruno,
W. Fulgione,
P Galeotti,
M. Garbini, [......],
V. G. Ryasny,
O. G. Ryazhskaya,
O. Saavedra,
G Sartorelli,
M. Selvi,
C. Vigorito,
L Votano,
V. F. Yakushev,
G. T. Zatsepin,
A. Zichichi
[show abstract]
[hide abstract]
ABSTRACT: In this paper we show the capabilities of the Large Volume Detector (INFN Gran Sasso National Laboratory) to identify a neutrino burst associated to a supernova explosion, in the absence of an "external trigger", e.g., an optical observation. We describe how the detector trigger and event selection have been optimized for this purpose, and we detail the algorithm used for the on-line burst recognition. The on-line sensitivity of the detector is defined and discussed in terms of supernova distance and electron anti-neutrino intensity at the source. Comment: Accepted for pubblication on Astroparticle Physics. 13 pages, 10 figures
10/2007;
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N.Yu. Agafonova,
M. Aglietta,
P. Antonioli,
G. Bari,
A. Bonardi, V.V. Boyarkin,
G. Bruno,
W. Fulgione,
P. Galeotti,
M. Garbini, [......],
O.G. Ryazhskaya,
O. Saavedra,
G. Sartorelli,
M. Selvi,
C. Vigorito,
L. Votano,
V.F. Yakushev,
G.T. Zatsepin,
A. Zichichi,
The LVD Collaboration
[show abstract]
[hide abstract]
ABSTRACT: The CERN Neutrino to Gran Sasso (CNGS) project aims to produce a high energy, wide band νμ beam at CERN and send it toward the INFN Gran Sasso National Laboratory (LNGS), 732km away. Its main goal is the observation
of the ντ appearance, through neutrino flavour oscillation. The beam started its operation in August 2006 for about 12 days: a total
amount of 7.6×1017 protons were delivered to the target. The LVD detector, installed in hall A of the LNGS and mainly dedicated to the study
of supernova neutrinos, was fully operating during the whole CNGS running time. A total number of 569 events were detected
in coincidence with the beam spill time. This is in good agreement with the expected number of events from Monte Carlo simulations.
European Physical Journal C 01/2007; 52(4):849-855. · 3.63 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: The major purpose of the experiments performed on the Russian-Italian Large Volume Detector (LVD) located at the Gran Sasso
Underground Laboratory (Italy) is to search for neutrino bursts from gravitational collapses of stars in our Galaxy. The estimates
obtained for the numbers of neutrino interactions occurring in the LVD structure in the case of collapses developing by different
scenarios at the center of the Galaxy and the efficiencies of detection of these interactions for different neutrino energies
are presented.
Bulletin of the Russian Academy of Sciences Physics 01/2007; 71(4):573-576.
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[show abstract]
[hide abstract]
ABSTRACT: The large-volume detector operating at the Gran Sasso National Laboratory, Italy, is intended primarily for detecting neutrinos
from gravitational collapses in the Galaxy. The apparatus consisting of scintillation detectors, with a total scintillator
mass of ∼1 kt, interleaved with iron (∼1 kt) has been collecting data since 1992. No candidates for neutrino bursts from collapsing
stars have been found. The new upper limit of the frequency of supernova bursts in the Galaxy is reported. The results of
the investigation of the space distribution of muon-produced neutrons are presented, and the possibilities for determining
the charge composition of muon fluxes with energies E
μ > 5 TeV are considered.
Bulletin of the Russian Academy of Sciences Physics 01/2007; 71(4):570-572.
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N. Yu. Agafonova,
M Aglietta,
P. Antonioli,
G Bari, V. V. Boyarkin,
G Bruno,
W. Fulgione,
P Galeotti,
M. Garbini,
P. L. Ghia, [......],
O. G. Ryazhskaya,
O. Saavedra,
G Sartorelli,
M. Selvi,
C. Vigorito,
F. Vissani,
L Votano,
V. F. Yakushev,
G. T. Zatsepin,
A. Zichichi
[show abstract]
[hide abstract]
ABSTRACT: The LVD detector, located in the INFN Gran Sasso National Laboratory (Italy), studies supernova neutrinos through the interactions with protons and carbon nuclei in the liquid scintillator and interactions with the iron nuclei of the support structure. We investigate the effect of neutrino oscillations in the signal expected in the LVD detector. The MSW effect has been studied in detail for neutrinos travelling through the collapsing star and the Earth. We show that the expected number of events and their energy spectrum are sensitive to the oscillation parameters, in particular to the mass hierarchy and the value of $\theta_{13}$, presently unknown. Finally we discuss the astrophysical uncertainties, showing their importance and comparing it with the effect of neutrino oscillations on the expected signal.
10/2006;
-
N.Yu. Agafonova,
M. Aglietta,
P. Antonioli,
G. Bari, V.V. Boyarkin,
G. Bruno,
W. Fulgione,
P. Galeotti,
M. Garbini,
P.L. Ghia, [......],
O.G. Ryazhskaya,
O. Saavedra,
G. Sartorelli,
M. Selvi,
C. Vigorito,
F. Vissani,
L. Votano,
V.F. Yakushev,
G.T. Zatsepin,
A. Zichichi
[show abstract]
[hide abstract]
ABSTRACT: The LVD detector, located in the INFN Gran Sasso National Laboratory (Italy), studies supernova neutrinos through the interactions with protons and carbon nuclei in the liquid scintillator and interactions with the iron nuclei of the support structure. We investigate the effect of neutrino oscillations in the signal expected in the LVD detector. The MSW effect has been studied in detail for neutrinos travelling through the collapsing star and the Earth. We show that the expected number of events and their energy spectrum are sensitive to the oscillation parameters, in particular to the mass hierarchy and the value of θ13, presently unknown. Finally we discuss the astrophysical uncertainties, showing their importance and comparing it with the effect of neutrino oscillations on the expected signal. We do not discuss in this paper the determination of oscillation parameters from the results of the observations; this task seems to be very difficult until astrophysical uncertainties are significantly reduced.
Astroparticle Physics.
-
N.Yu. Agafonova,
M. Aglietta,
P. Antonioli,
G. Bari,
A. Bonardi, V.V. Boyarkin,
G. Bruno,
W. Fulgione,
P. Galeotti,
M. Garbini, [......],
V.G. Ryasny,
O.G. Ryazhskaya,
O. Saavedra,
G. Sartorelli,
M. Selvi,
C. Vigorito,
L. Votano,
V.F. Yakushev,
G.T. Zatsepin,
A. Zichichi
[show abstract]
[hide abstract]
ABSTRACT: In this paper we show the capabilities of the Large Volume Detector (INFN Gran Sasso National Laboratory) to identify a neutrino burst associated with a supernova explosion, in the absence of an “external trigger”, e.g., an optical observation. We describe how the detector trigger and event selection have been optimized for this purpose, and we detail the algorithm used for the on-line burst recognition. The on-line sensitivity of the detector is defined and discussed in terms of supernova distance and intensity at the source.
Astroparticle Physics.
-
N Yu Agafonova,
M Aglietta,
P Antonioli,
G Bari,
A Bonardi, V V Boyarkin,
G Bruno,
W Fulgione,
P Galeotti,
M Garbini, [......],
V G Ryasny,
O G Ryazhskaya,
O Saavedra,
G Sartorelli,
M Selvi,
C Vigorito,
L Votano,
V F Yakushev,
G T Zatsepin,
A Zichichi
[show abstract]
[hide abstract]
ABSTRACT: The Cern Neutrino to Gran Sasso (CNGS) project aims to produce a high energy, wide band ¢ ¡ beam at Cern and send it towards the INFN Gran Sasso National Laboratory (LNGS), £ ¥ ¤ ¦ km away. Its main goal is the observation of the äppearance, through neutrino flavour oscillation. The beam started its operation in August 2006 for about 12 days: a total amount of £ © protons were delivered to the target. The LVD detector, installed in hall A of the LNGS and mainly dedicated to the study of supernova neutrinos, was fully operating during the whole CNGS running time. A total number of ¢ ! events were detected in coincidence with the beam spill time. This is in good agreement with the expected number of events from Montecarlo simulations.
