Search

The LVD detector, located in the Gran Sasso Laboratory at a depth of 3600 m w.e., is designed for research in the field of neutrino physics, astrophysics, cosmic ray physics and the search for rare processes predicted by theory. The LVD experiment was built in 1991 to detect neutrinos from collapses of stellar nuclei in our galaxy. The background of the detector is atmospheric muons, neutrons generated by muons in the detector material and natural radioactivity underground. The report presents the latest experimental results obtained at LVD: a limit on the frequency of supernova outbreaks, muon variations with a period of 1, 4, 10 years, and also describes the problems of studying the low-energy background underground. [ABSTRACT FROM AUTHOR]

Time series of gamma-ray photons from natural radioactivity measured with the Large Volume Detector (LVD) at the Gran Sasso underground laboratory (Laboratori Nazionali del Gran Sasso, Italy) have been analyzed. The instrument is used to detect neutrinos from gravitational collapses of stellar cores in the Galaxy. The background of the experiment is due to neutrons and gamma-ray photons from the decays of daughter nuclei of uranium and thorium. An analysis of periodic variations of the number of gamma-ray photons caused by the radon concentration in the underground laboratory has shown the presence of diurnal, weekly, monthly, and annual modulations. Data collected from 2004 to 2021, including a period of low activity in the hall of the Gran Sasso laboratory during the COVID-19 pandemic, have been reported. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Selected results from the multipurpose Large Volume Detector (LVD) are presented. Investigations at the LVD setup are being performed according to the program of continuous searches for neutrinos from supernova explosions in the Milky Way Galaxy and muon- and neutron-physics programs. At the present time, the LVD setup is the largest scintillation detector, which possesses a unique potential for studies in the realms of underground physics. [ABSTRACT FROM AUTHOR]

The current status of the LVD (large volume detector) experiment aimed at search for neutrinos from the gravitational collapse of stellar cores is described. Within the period of observations from June 1992 to February 2017, no gravitational collapse was found in the Milky Way Galaxy and Magellanic Clouds, including hidden ones (not ejecting the envelope). The LVD collects data for 99% of the live time. A limit on the frequency of supernova bursts within a distance of 25 kpc was set at a level of 0.1 event/yr. The most recent results obtained by studying the muon component of cosmic rays are presented. [ABSTRACT FROM AUTHOR]