Fragmentation

Perturbative QCD (pQCD) has proved to be a very successful theory in its application to hard processes. This enables the theory to be employed as a tool to tackle more complicated problems. One of these concerns the soft limit of QCD and colour confinement. Presently, multihadron production phenomena cannot be derived in a systematic way solely from perturbation theory without additional model-dependent assumptions.

To investigate the limits of applicability of pQCD it is important to determine to what extent semi-soft phenomena in hard processes still reflect the properties of the perturbative evolution phase. This line of research, initiated almost 15 years ago [1,2], has reached a high level of sophistication (see [3] for a recent review) and, as witnessed at this workshop, continues to inspire analyses in all major high-energy experiments. This summary deals with some of the most interesting results.