arXiv subjects

A. V. Sabourov

Publications and source records attributed to A. V. Sabourov.

17 recordsLinked to original sources

arXiv2026

The puzzle of composition of cosmic rays with energies (2-12.5) EeV according to muon detectors data of the Yakutsk EAS array

The results of a study of the cosmic ray composition in individual events in the energy range (2-12.5) EeV using the muon correlation method is presented. The considered sample included showers with zenith angles less than 60 degrees recorded in the period 1974-2018. The existence of four separate groups of primary particles with different origins is confirmed. The obtained results have potential importance for understanding the composition of cosmic rays in the specified primary energy range.

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arXiv2024

A Direct Comparison of Muon Measurements at the Yakutsk Array and the Pierre Auger Observatory

Here we consider the results of direct measurements of muons in extensive air showers with zenith angles $θ\le 45^{\circ}$ and energy above $10^{17}$ eV, obtained at the Pierre Auger Observatory and Yakutsk array. In both experiments muons were registered with underground scintillation detectors with $\approx 1.0 \times \secθ$ GeV energy threshold. Measured density values were compared to theoretical predictions calculated within the framework of the QGSJet-II.04 hadron interaction model. They differ by factor $1.53 \pm 0.13$(stat). We demonstrate that this difference is due to overestimation of muon densities by 1.22 times and underestimation of primary energy by 1.25 times in the Auger experiment.

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arXiv2023

Muon puzzle in ultra-high energy EASs according to Yakutsk array and Auger experiment data

The lateral distribution of particles in extensive air showers from cosmic rays with energy above $10^{17}$ eV registered at the Yakutsk complex array was analyzed. Experimentally measured particle densities were compared to the predictions obtained within frameworks of three ultra-high energy hadron interaction models. The cosmic ray mass composition estimated by the readings of surface-based and underground detectors of the array is consistent with results based on the Cherenkov light lateral distribution data. A comparison was made with the results of direct measurement of the muon component performed at the Pierre Auger Observatory. It is demonstrated that the densities of muon flux measured at Yakutsk array are consistent with results of fluorescent light measurements and disagree with results on muons obtained at the Auger array.

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arXiv2023

Muons in EASs with $E_0 = 10^{19}$ eV according to data of the Yakutsk Array

Lateral distribution functions of particles in extensive air showers with the energy $E_0 \simeq 10^{19}$ eV recorded by ground-based and underground scintillation detectors with a threshold of $E_μ \simeq 1.0 \times \secθ$ GeV at the Yakutsk array during the continuous observations from 1986 to 2016 have been analyzed using events with zenith angles $θ\le 60^{\circ}$ functions have been compared to the predictions obtained with the QGSJet01 hadron interaction model by applying the CORSIKA code. The entire dataset indicates that cosmic rays consist predominantly of protons.

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arXiv2023

Zenith-Angular Characteristics of Particles in EASs with $E_0 \simeq 10^{18}$ eV According to the Yakutsk Array Data

Particle lateral distributions were investigated in cosmic ray air showers with energy $E_0 \simeq 10^{18}$ eV registered at the Yakutsk array with surface and underground scintillation detectors with $\simeq 1 \times \secθ$~GeV threshold during the period of continuous observations from 1986 to 2016. The analysis covers events with arrival direction zenith angles $θ\le 60^{\circ}$ within five intervals with step $Δ\cosθ= 0.1$. Experimental values were compared to simulation results obtained with the use of CORSIKA code within the framework of QGSJet01 hadron interaction model. The whole dataset points at probable cosmic ray composition which is close to protons.

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arXiv2023

Content of muons in extensive air showers measured by Yakutsk array

Lateral distribution of muons in extensive air showers registered at the Yakutsk array was investigated. The analysis covers two periods of observation: before 2018 and after 2020, when the revision of muon detectors with 1-GeV threshold was complete. Measured values of muon density are compared to computational results obtained within the framework of two hadron interaction models. Within the energy domain above $10^{18}$ eV the best agreement is observed for proton composition primary cosmic rays.

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arXiv2023

Energy Spectrum of Ultrahigh-Energy Cosmic Rays according to Data from Ground-Based Scintillation Detectors of the Yakutsk EAS Array

Results obtained from an analysis of the energy spectrum of cosmic rays with energies in the region of $E_0 \ge 10^{17}$ eV over the period of continuous observations from 1974 to 2017 are presented. A refined expression for estimating the primary-particle energy is used for individual events. This expression is derived from calculations aimed at determining the responses of the ground-based and underground scintillation detectors of the Yakutsk array for studying extensive air showers (EAS) and performed within the QGSJET01, QGSJET-II-04, SIBYLL-2.1, and EPOS-LHC models by employing the CORSIKA code package. The new estimate of $E_0$ is substantially lower than its counterpart used earlier.

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arXiv2021

Status of the Yakutsk air shower array and future plans

The Yakutsk Extensive Air Shower Array has been continuously operating for more than 50 years (since 1970) and up until recently it has been one of world's largest ground-based instruments aimed at studying the properties of cosmic rays in the ultra-high energy domain. In this report we discuss results recently obtained at the array - on cosmic rays energy spectrum, mass composition and directional anisotropy - and how they fit into the world data. Special attention is paid to the measurements of muonic component of extensive air showers. Theoretical results of particle acceleration at shocks are also briefly reviewed. Future scientific and engineering plans on the array modernization are discussed.

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arXiv2014

Large-scale distribution of cosmic rays in right ascension as observed by the Yakutsk array at energies above $10^{18}$ eV

We present the results of searches for anisotropy in the right ascension ($RA$) distribution of arrival directions of cosmic rays (CRs) detected with the Yakutsk array during the 1974--2008 observational period in the energy range above $10^{18}$ eV. Two methods of analysis are applied to two sub-samples of the data. Particularly, estimations of the first and second harmonic amplitudes are given, as well as the first harmonic phase in adjacent energy intervals. Analysis of variance demonstrates a significant contraction of the minimal width of the $RA$ distribution in the energy bin $(10^{19},1.78\times10^{19})$ eV with respect to the isotropic distribution, which may be attributed to a possible source of CRs within the interval $RA\in(15^0,45^0)$.

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arXiv2007

Average mass composition of primary cosmic rays in the superhigh energy region by Yakutsk complex EAS array data

The characteristics relating to the lateral and longitudinal development of EAS in the energy region of 10^15-10^19eV have been analyzed in the framework of the QGSJET model and of mass composition of primary cosmic rays. It is found that at E(0) >= 5*10^15eV the mean mass composition of primary cosmic rays begins to vary as indicated by a rise of with increasing energy. The maximum value of is observed at E(0) ~ (5-50)*10^16eV. It is confirmed by data of many compact EAS arrays and does not contradict an anomalous diffusion model of cosmic ray propagation in our Galaxy. In the superhigh energy region (>=10^18eV) the value begins to decrease, i.e. the mass composition becomes lighter and consists of protons and nuclei of He and C. It does not contradict our earlier estimations for the mass composition and points to a growing role of the metagalactic component of cosmic rays in the superhigh energy region.

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arXiv2007

Cosmic ray spectrum by energy scattered by EAS particles in the atmosphere and galactic model

The differential energy spectrum of cosmic rays from Cherenkov radiation measurements in EAS in the energy range of 10^15-10^20eV has been compared with an anomalous diffusion model for the particles in interstellar space having fractal properties (Lagutin et al, 2001). The close association between experimental data and calculated "all particle" spectra in form at E(0) (10^15-10^18)eV is found. In this case, the average mass composition of cosmic rays calculated by five components does not contradict the average mass composition from experimental data which was obtained by several of EAS characteristics in that energy region.

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arXiv2007

A shape of charged particle lateral distribution in individual EAS events with energy above 10^19 eV arriving from different celestial regions

A shape of lateral distribution for charged particles in events with energy above 10^19eV is considered. Two methods were used for individual LDF parametrization. In the first approach, the index of power was determined for generalized Greisen-Linsley approximation. In second, mean square radius of the shower was determined for approximation proposed by Lagutin et al. Comparison of resulted parameters is presented for individual events arrived from different celestial regions -- Galactic planes and the region with increased flux of particles with E(0)>=10^19eV (according to Yakutsk array): 1.7h-3.7h right ascension; 45-60 degrees declination.

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arXiv2007

Behavior of some characteristics of EAS in the region of knee and ankle of spectrum

The energy dependence of such characteristics as a ratio of the total number of charged particles to the total flux of EAS Cherenkov radiation, a ratio of E(thr)>=1GeV muon flux density at the distance of 600m from a shower core to charged particle flux density, a ratio of the energy transferred to the electromagnetic component of EAS to the primary particle energy is presented. Their comparison with two-component mass composition of cosmic rays (p-Fe) in the framework of calculations by a QGSJET model is given.

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arXiv2006

Recent results from Yakutsk experiment: development of EAS, energy spectrum and primary particle mass composition in the energy region of 10^15-10^19 eV

Experimental data obtained at the Yakutsk array after the modernization in 1993 are analyzed. The characteristics of EAS longitudinal and radial development found from the charged particle flux and EAS Cherenkov light registered at the Yakutsk complex array are presented. The energy spectrum of EAS obtained from Cherenkov light and an estimate of the PCR mass composition are presented.

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arXiv2004

Cosmic Rays with Energy Above 10^{17} ev

The energy spectrum of primary cosmic rays with ultra high energies based on the Yakutsk EAS Array data is presented. For the largest events values of S600 and axis coordinates have been obtained using revised lateral distribution function. The affect of the arrival time distribution at several axis distance on estimated density for Yakutsk and AGASA is considered.

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arXiv2004

Spectrum of cosmic rays with energy above $10^{17}$ eV

There are some discrepancies in the results on energy spectrum from Yakutsk, AGASA, and HiRes experiments. In this work differential energy spectrum of primary cosmic rays based on the Yakutsk EAS Array data is presented. For the largest events values of $S_{600}$ and axes coordinates have been obtained using revised lateral distribution function. Simulation of converter's response at large distances showed no considerable underestimation of particle density. Complex shape of spectrum in region of $\E > 10^{17}$ eV is confirmed. After adjustment of parameters and additional exposition at the Yakutsk array there are three events with energy $\E > 10^{20}$ eV.

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arXiv2004

The spectrum features of UHECRs below and surrounding GZK

The energy spectrum of UHECRs is discussed on the basis of the Yakutsk array database analysis. In the region E=0.1 to 30 EeV the showers are detected under trigger-500, while at energies above 30 EeV the whole acceptance area for trigger-1000 is used in order to utilize all the data available in the region of GZK cutoff.

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