Search

The Baksan Neutrino Observatory setups are currently performing search for neutrino and ultra-high-energy gamma-ray counterparts of the events on the Gamma-ray Coordinates Network. The Gamma-ray Coordinates Network is a system for distributing alerts from gamma-ray bursts, transients. Muon neutrinos and antineutrinos with energies above 1 GeV are registered with the Baksan Underground Scintillation Telescope. Ultra-high-energy gamma rays are registered with the "Carpet-2" setup. Registration of events and analysis of alerts occurs in near-real time. Alerts from Swift BAT, Fermi-GBM, Fermi-LAT, INTEGRAL, IceCube, HAWC are used. This work presents the description of the alert processing program and preliminary results. [ABSTRACT FROM AUTHOR]

Carpet-2 is an air-shower array at Baksan Valley, Russia, equipped with a large-area (175 m2) muon detector, which makes it possible to separate primary photons from hadrons. We report the first results of the search for primary photons with energies Eγ > 1 PeV, directionally associated with IceCube high-energy neutrino events, in the data obtained in 3080 days of Carpet-2 live time. [ABSTRACT FROM AUTHOR]

This contribution describes the current progress on the composition analysis of data recorded with Carpet EAS detector. The focus of the paper is on the methodological side of analysis. [ABSTRACT FROM AUTHOR]

The experimental data of the Andyrchy-BUST experiment are presented. The three types of experimental data, taken in our experiment, have been analyzed: high energy muon number spectrum, EAS size spectrum and dependence of the mean number of high energy muons on EAS size. Joint analysis of these experimental data have been used for both studying the primary composition and testing interaction models. [ABSTRACT FROM AUTHOR]

Experimental data obtained with the aid of the Baksan underground scintillation telescope over a long period of its operation are analyzed with the aim of searches for an excess flux of ultrahigh-energy (≥100 TeV)muons. The multiple-interaction method, which is based on the ideas of the pair-meter technique, is used to analyze the energy spectrum of the muons. The phenomenological parameters of this method and its sensitivity to the shape of the spectrum are discussed. The experimental distributions are compared with the results of calculations for various versions of the muon spectrum. The possibility of separating ultrahigh-energy muons that fly in the vicinity of the axis of extensive air showers is assessed on the basis of the integrated number of recorded and simulated events featuring large energy depositions. [ABSTRACT FROM AUTHOR]

The Andyrchy facility was created for studying the energy spectrum and nuclear composition of primary cosmic rays in the region of a knee in the cosmic-ray spectrum. The position of this facility above the Baksan underground scintillation telescope allows simultaneous detection of electron-photon and high-energy muon components of extensive air showers. The parameters of this facility also allow it to be used for solving a number of other problems of cosmic-ray physics. Data since 1996 have been collected for several physical problems. The facility is described, and its performance characteristics are presented. [ABSTRACT FROM AUTHOR]

The project of the Baksan Underground Scintillation Telescope (BUST) upgrade is presented. Additional outer layers of the detectors with fine spatial resolution will be mounted around BUST. Optimal dimensions of a counter, 0.125m x 0.125m x 0.03m were chosen with a simulation program. The functional diagram of BUSTs DAQ additional layers is presented. Modernization allows us to study the knee region using muon number spectrum measurements. [ABSTRACT FROM AUTHOR]

Knee formation in the EAS size spectrum as a possible result of some portion of EAS's energy carried away by some missing EAS component is discussed. To explain the absence of the bump in calculated EAS size spectrum for the standard EAS development in the present day experiments, the model of "catastrophic" EAS development was proposed. The hypothesis that all the energy lost for the further shower development ELT finally passes into neutrino (¾ELT) and muons (¼ELT) is shown to be practically excluded by present experimental data. [ABSTRACT FROM AUTHOR]

Abstract: The knee is a change in the slope of the cosmic ray spectrum at approximate energy of 3 PeV. There are multiple competing models for the knee giving conflicting predictions about this change for different masses of the primary particle. Accurate mass measurements of cosmic rays spectra around 3 PeV would be able to exclude some of these models. Cosmic-ray experiment EMMA uses a new method for studying the composition of cosmic rays at the knee area. It is able to determine the multiplicity, the lateral distribution, and the arrival direction of incoming muons produced early in the shower evolution on an event-by-event basis and deduce from these measurements the mass and the energy of the primary particle. EMMA is situated at the depth of 75 m in the Pyhäsalmi mine, Finland. This rock overburden, which corresponds to 210 m of water equivalent, gives EMMA a cut-off energy of 50 GeV for vertical muons. Since the simulations using different air-shower models give similar predictions for the lateral distribution of these high energy muons, we are confident that EMMA should yield a reliable and an air-shower model independent data on the composition of cosmic rays around the knee region. [Copyright &y& Elsevier]