Muons with E_th >= 1 Gev and Mass Composition in the Energy Range 10^{18}-10^{20} ev Observed by Yakutsk Eas Array

• Main Authors: Knurenko, S. P., Kolosov, V. A., Makarov, I. T., Sleptsov, I. Ye., Sleptsova, V. R., Struchkov, G. G.
• Format: Text
• Language: unknown
• Published: arXiv 2004
• Subjects: Astrophysics astro-ph; FOS Physical sciences; Yakutsk
• Online Access: https://dx.doi.org/10.48550/arxiv.astro-ph/0411683; https://arxiv.org/abs/astro-ph/0411683

The ratio of the muon flux density to charged particle flux density at distances of 300 and 600 m from the shower axis ($\rhom(300)/\rhos(300)$ and $\rhom(600)/\rhos(600)$) is measured. In addition, the energy dependence of $\rhom(1000)$ is analysed for showers with energies above $10^{18}$ eV. A comparison between the experimental data and calculations performed with the QGSJET model is given for the cases of primary proton, iron nucleus and gamma- ray. We conclude that the showers with $\E\ge3\times10^{18}$ eV can be formed by light nuclei with a pronounced fraction of protons and helium nuclei. It is not excluded however that a small part of showers with energies above $10^{19}$ eV could be initiated by primary gamma-rays. : 19th European Cosmic Ray Symposium, Aug 30 - Sep 3 2004, Florence, Italy. 3 pages, 1 figure. Submitted for publication in International Journal of Modern Physics A