Indications of Anisotropy of Cosmic-Ray Elemental Groups Based on KASCADE Data

Abstract In this work, we study the anisotropy of elemental groups of cosmic rays using data from the KASCADE experiment. The problems of determining primary energy and mass associated with fluctuations in the development of extensive air showers are discussed in detail. To address these issues, a method is used that suppresses the influence of these fluctuations on the estimation of primary energy and mass. The proposed approach is based on the use of lessening fluctuation curves, whose behavior is largely insensitive to shower-to-shower fluctuations during the development of extensive air showers. This allows, firstly, to significantly reduce errors in primary energy estimation and, secondly, to analyze individual showers. The approach also enables simultaneous analysis of showers arriving at substantially different zenith angles θ . To study cosmic-ray anisotropy, we analyzed right ascension versus declination distributions for five elemental groups (p, He, C, Si, and Fe). Analysis of experimental data from the KASCADE collaboration revealed significant differences in the distributions of these groups in equatorial coordinates, which may indicate a directed structure in cosmic-ray fluxes of different elemental composition. The observed features may point to the influence of nearby spiral arms and the Galactic magnetic field structure on the propagation of cosmic rays.