Koba-Nielsen-Olesen scaling and production mechanism in high-energy collisions

An analysis of the existing data on photoproduction and electroproduction of protons is made. Koba-Nielsen-Olesen (KNO) scaling is observed in both cases. The scaling function of the nondiffractive $\gamma p$ processes turns out to be the same as that for nondiffractive hadron-hadron collisions, but the scaling function for deep-inelastic $e^{-}p$ collisions is very much different from that for $e^{-}{e}^{+}$ annihilation processes. Taken together with the observed difference in KNO scaling functions in $e^{-}{e}^{+}$ annihilation and nondiffractive hadron-hadron processes these empirical facts provide further evidence for the conjecture: The KNO scaling function of a given collision process reflects its reaction mechanism. Arguments for this conjecture are given in terms of a semiclassical picture. It is shown that, in the framework of the proposed picture, explicit expressions for the above-mentioned KNO scaling functions can be derived from rather general assumptions.