Sources of seasonal temperature variations in the average energy of the muon flux detected in the LVD experiment have been discussed. It has been shown that variations are due to the processes of ...generation of muons in upper layers of the atmosphere and the passage of muons through a thick rock layer.
During the SN1987A explosion on February 23, 1987, four underground neutrino detectors and two gravitational antennas in Rome and Maryland detected signals associated with the gravitational collapse ...of the star’s core. Because it is impossible to detect direct gravitational radiation from the collapse of SN1987A with antennas, it is still unclear what events were recorded by gravitational antennas. In this work, an amplitude analysis of the signals from gravitational antennas in Rome and Maryland in the vicinity of the signals from neutrino detectors during Supernova SN1987A was carried out. It is shown that the amplitude distributions in all antenna signals are consistent with the distribution of fluctuating energy losses of atmospheric muons crossing the antennas. A conclusion has been made about the muon origin of signals Weber type antennas, aluminized cylinders with a mass of 2–3 t.
The processes of the generation of cosmogenic neutrons (cg-neutrons) underground are considered. The neutrons produced by cosmic-ray muons in their interactions with matter are called cosmogenic. ...Deep-inelastic π
A
-collisions of pions in muon-induced hadronic showers are mainly their source at energies above 30 MeV. The characteristics of the energy spectrum for the generation of cg-neutrons have been determined by invoking the additive quark model of deep-inelastic soft processes and the mechanism for the interactions of high-energy nucleons in a nucleus. The three-component shape of the spectrum is explained, and the energy of the “knee” in the spectrum has been found to depend on the mass number
A
. The peculiarities of deep-inelastic π
A
-scattering lead to the conclusion that the spectrum of cg-neutrons steepens sharply at energies above 1 GeV. The calculated quantitative characteristics of the spectrum are compared with those obtained in measurements.
The parameters of the seasonal modulations in the intensity of muons and cosmogenic neutrons generated by them at a mean muon energy of 280 GeV have been determined in the LVD (Large Volume Detector) ...experiment. The modulations of muons and neutrons are caused by a temperature effect, the seasonal temperature and density variations of the upper atmospheric layers. The analysis performed here leads to the conclusion that the variations in the mean energy of the muon flux are the main source of underground cosmogenic neutron variations, because the energy of muons is more sensitive to the temperature effect than their intensity. The parameters of the seasonal modulations in the mean energy of muons and the flux of cosmogenic neutrons at the LVD depth have been determined from the data obtained over seven years of LVD operation.
Characteristics of cosmogenic neutrons, such as the yield, production rate, and flux, were determined for a standard rock. The dependences of these quantities on the standard-rock depth and on the ...average muon energy were obtained. These properties and dependences make it possible to estimate easy the muon-induced neutron background in underground laboratories for various chemical compositions of rock.
The Large-Volume scintillation Detector commonly known as LVD and located at the Gran Sasso Laboratory at an average depth of 3650 m w.e. measures muons of intensity
m
s
. The results obtained from ...an analysis of the properties of seasonal variations of the horizontal and vertical muon fluxes are presented in this article. Horizontal muons detected in LVD mostly correspond to rock depths of about 5 km w.e. and zenith angles
of about
, while vertical muons (
) correspond to depths of about 4.6 km w.e.
Using the Geant4 code, we have performed a full-scale simulation of the LSD response to the neutrino burst from SN 1987A. The neutrino flux parameters were chosen according to one of the models: the ...standard collapse model or the rotational supernova explosion model. We showed that, depending on the chosen parameters, one can either obtain the required number of pulses in the detector or reproduce their energy spectrum, but not both together. The interaction of neutrino radiation both with LSD itself and with the material of the surrounding rock was taken into account in our simulation. We also explored the hypothesis that the entire unique LSD signal at 2:52 UT was produced by neutrino fluxes from the surrounding granite. However, this hypothesis was not confirmed by our simulation. The results obtained provide a rich material for possible interpretations.
A change in the law of attraction in some regimes is predicted in the modified gravity models being actively developed at present. The set of up-to-date observational data leaves a wide range of ...admissible parameters for the theory. In this paper, we consider the possibility that the signal recorded by the Geograv resonant gravitational-wave detector in 1987 during the explosion of SN 1987A was produced by an abrupt change in the metric during the passage of a powerful neutrino flux through the detector. Such an impact on the detector is possible, in particular, in extended scalar–tensor theories in which the local matter density gradient affects the gravitational force. The first short neutrino pulse emitted at the initial stage of stellar core collapse before the onset of neutrino opacity could exert a major influence on the detector, because it could produce the detector response at the first resonance frequency. In contrast, the influence of the subsequent broad pulse (with a duration of several seconds) in the resonant detector is exponentially suppressed, despite the fact that the second pulse carries an order-of-magnitude more neutrino energy, and it could generate a signal in the LSD neutrino detector. This explains the time delay of 1.4 s between the Geograv and LSD signals. The consequences of this effect of modified gravity for future LIGO/Virgo observations are discussed.
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