Flat Proton Spectrum and Its Implications

Abstract
The longitudinal momentum distribution of the final detected proton in pp inclusive reactions is flat for energies ranging from 20 to 1500 GeV. We show how this can be understood in the diffractive model, and how this information provides a way for calculating the average multiplicity and the pion longitudinal momentum distributions in pp inclusive reactions. No arbitrary parameter is used. The agreement with experiment is remarkably good.