SYSTEMATICS OF LEADING PARTICLE-PRODUCTION - ART. NO. 094034

Using a QCD-inspired model developed by our group for particle product ion, the interacting gluon model (IGM), we have made a systematic anal ysis of all available data on leading particle spectra. These data inc lude diffractive collisions and photoproduction at DESY HERA. With a s mall number of parameters (essentially only the nonperturbative gluon- gluon cross section and the fraction of diffractive events) good agree ment with data is found. We show that the difference between pion and proton leading spectra is due to their different gluon distributions. We predict a universality in the diffractive leading particle spectra in the large momentum region, which turns out to be independent of the incident energy and of the projectile type. [S0556-2821(98)08121-1].