High energy interactions of cosmic rays

Abstract

A discussion of a number of important topics related to modeling of high energy cosmic ray interactions is presented. Special attention is devoted to novel theoretical approaches employed in event generators of hadronic interactions and to the impact of experimental data from the Large Hadron Collider (LHC). In relation to studies of ultra-high energy cosmic rays (UHECRs), differences between various predictions for basic characteristics of UHECR-induced extensive air showers in the atmosphere are analyzed and traced down to differences in the respective treatments of hadronic interactions. Possibilities to discriminate between the alternative approaches, based on LHC and UHECR data, are demonstrated and the relation to UHECR primary composition is outlined. Finally, in relation to direct studies of charged cosmic rays, potential improvements of the treatment of cosmic ray interactions at low and intermediate energies are discussed.