ABSTRACT
This work has thus far specifically avoided discussing how the study of EAS can give information of interest to high energy physics. The reason is our emphasis on the astrophysical implications of the study of cosmic rays plus the difficulty in extracting reliable information on hadronic interactions. Because of the low flux at ultrahigh energies, it is extremely difficult to study any but the most common processes. The proton-air inelastic total cross section ( σ p − a i r i n e l ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429499654/40d6b4bb-1bca-4c1e-8c99-792ac2d1f6a9/content/eq178.tif"/> is probably the most straightforward measurement one can perform. The relation between it and the quantity which is more interesting for high energy physics, the proton-proton total cross section ( σ p p t o t ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429499654/40d6b4bb-1bca-4c1e-8c99-792ac2d1f6a9/content/eq179.tif"/> , is very model dependent. However, the energy dependence of the total cross section can be more reliably determined.
