High-Energy Nuclear Scattering and Regge Poles

In general, for a system of many nucleons, a sizable fractional increase of cross section requires the effectivee nucleon area to be comparable to the are aof the system (β^2 ~1). Thus, even for a light nucleus, enormous energies are required for the increase to be easily observable. However, at the highest cosmic-ray energies, the effect may be of importance. At 10^6 Bev, treating air like carbon, we predict a 25% increase in the absorption cross section of air over the value at 10Bev. It is interesting that Nikolskii et al. [9] have reported a change in the character of extensive air showers in the same energy region, indicating an increase in the absorption coefficient of air. The result has not been confirmed by other laboratories.