Fragmentation in the Central Region

The question of whether there may exist a discontinuity at x = 0 in the-pion spectrum of an inclusive reaction initiated by two unequal particles is raised. While such an occurrence is impossible in a model with only short-range correlations, it is a distinct possibility in the diffractive excitation model when the energy is high enough. We relate the discontinuity to the properties of the spectra of single diffractive excitations. Arguments are given as to why the discontinuity, if it exists, is not likely to be substantial. (Submitted to Physics Letters. Also submitted to the XVI International Conference on High Energy Physics, Batavia, Illinois, Sept. 6-13, 1972) * VVork supported in part by the U. S. Atomic Energy Commission.