Is pionization universal

Jet universality, restricted to the pionization region, is discussed both from the theoretical and experimental points of view. We review the notion of topological jets corresponding to hadronization of strings. We argue that the topological jet universality is broken by soft ''ladder'' gluons present in soft processes but not in hard ones. A multiperipheral model for quark jets which takes into account the spin 1/2 of the quark predicts a rapidity plateau of the same height as that of a hadron jet (for one cut Pomeron). We show that the q2 independence of in deep-inelastic lepton scattering favors this equality, which is contrary to topological jet universality. We propose a new test of the topological jet universality based on the local compensation of quantum numbers