Analysis of the mass composition of high-energy cosmic ray

Abstract

This paper analyses mass composition of high-energy cosmic ray, comparing simulation and experimental results. Using the nuclear interaction models QGSJET-II and Sibyll, we simulate EAS initiated by the primary nuclei representing all mass groups (p, He, O, Si, Fe). EAS is simulated for several energy levels between 1.1018 and 5.1019 eV. For such generated simulation data, we compute X-max distributions, mean X-max and RMS and compare these values with the experimental data from the Auger Experiment. The results show that for the 2-sigma confidence level, mass composition including nuclei from the CNO group and heavier can be fitted for Sibyll model only. For any combination of 3 and 4 primary particles, no model fits the experimental data at the 1-sigma confidence level. For the p + Fe bi-particle composition, or other combination of two particles, also no model fitting the experimental data can be found for the analysed energy interval.