QCD Universality recovered via the Total Available Quadri-Scalar: Atot
  After presenting a brief review of the phenomenology of the Leading Effect, we define a new variable, the ``Total Available Quadri-Scalar'' (Atot), and propose it as the invariant quantity effectively available for the production of the multihadronic final states. The introduction and the definition of this new variable are justified by means of simple geometrical-kinematical considerations and we show that Atot reduces to the so-called Effective Energy in the single specific situation where the use of the latter applies. Using Atot to re-plot existing data, the quantity <Nch> is shown to be a ``Universality Feature'' - that is, independent from the process under exam, the collider nominal energy, and even from the hadronic invariant mass - as imposed by QCD Universality. 
Corrado Appignani (Dipartimento di Fisica - Universita' di Bologna -   Bologna - Italy)