QCD-Motivated Description of Very High Energy Particle Interactions

Cross sections for the production of secondaries with large transverse momentum can become comparable to the total cross section in the TeV energy range. We argue that the onset of this effect is observed at sub-TeV energies via (i) an increase of the rapidity distribution near y = 0, (ii) an increase of T> with energy and, most directly, via (iii) a correlation between T> and multiplicity. If indeed scaling violations are associated with the hard scattering of partons, then scaling violations are largely confined to the central region and have little effect on cosmic ray data which are sensitive to the forward fragmentation region.