ABSTRACT
Experimental data comes from the detection and sampling of the extensive air shower (EAS) produced by a cosmic ray as it interacts in the atmosphere. EAS can be studied at the surface, beneath the earth, and at various mountain elevations. The longitudinal development of the shower in the atmosphere can be determined in an indirect fashion from the study of the lateral distribution. The time distribution of particles arriving at the surface as well as the Cherenkov light pulse rise time and width also carry information about the longitudinal development of the shower. Hadronic showers can be considered to be a superposition of individual electromagnetic showers produced by pi-zero decays and fed by the hadronic core. Hadronic EAS are modelled using coupled equations which describe how the nucleon component feeds the electromagnetic component as well as taking into account muon and neutrino production due to pion decays.
