Hadronic interactions and primary cosmic ray composition at energies 10¹⁵-10¹⁷eV

Abstract

A systematic simulation of atmospheric propagation of super high-energy cosmic rays has been carried out for studying the gamma-family phenomena observed by the mountain emulsion chamber experiment. By comparing with recently published experimental data the authors analysis shows that the two interaction models SD-SH and D-ND which fit collider data but possess different physical features and parameters, incorporating a moderate primary composition, describe the major behaviour of super high-energy cosmic ray cascades in the atmosphere. Conclusive results on the characteristics of hadronic interactions and the energy spectrum and chemical composition of primary cosmic rays at the energy region around 1015-1017 eV are summarised.