Multiplicity Distributions and the Frontier between Soft and Hard Physics

Abstract: The multiplicity distributions measured in proton proton collisions at the LHC exhibit interesting new features. One of them is the appearance of substructures, such as the so-called "shoulder" at large multiplicities. The most natural interpretation of this behavior is the existence of two production mechanisms. The final result is then a superposition of two distributions. In a previous publication we assumed that the two production mechanisms are soft and semihard partonics scatterings. In this work we further discuss this assumption and, in particular, we study the dependence of the results on the scale which separates soft from hard events.