Possible scenarios in hh collisions in the TeV region are discussed in full phase space. It is shown that at such high energies one should expect strong KNO scaling violation and a ln( √ s) increase of the average charged multiplicity of the semi-hard component, resulting in a huge mini-jet production. Dedication

Scenarios for particle production in the GeV and TeV regions are reviewed. The expected increase with the c.m. energy of the average number of clans for the soft component and the decrease for the semihard one indicate possible classical and quantum behavior of gluons, respectively. Clan thermodynamics, discussed in the paper, appears as the natural framework to deal with such phenomena.

In the framework of percolation of color sources, the transverse momentum distribution in heavy ion and p + p collisions at all centralities and energies are shown to follow a universal behaviour. The width of the distribution depends on the fluctuations of the number of color sources per cluster. At low densities, there are only independent single color sources, no fluctuations occurs and the distribution is described by a single exponential. At very high densities, only one cluster of many color sources appears and therefore there are not fluctuations either and the hardness of the distribution is suppressed. The Cronin effect in this framework is due to a maximum of the fluctuations which decreases as the density increases. We obtain a good agreement with experimental data including the low p T behaviour and the spectra for different particles.We show that the transverse momentum and multiplicity distributions are related to each other in a defined way. This point is satisfied by the experimental data on p + p collisions at different energies.

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This paper contains a review of the main results of a search of regularities in collective variables properties in multiparticle dynamics, regularities which can be considered as manifestations of the original simplicity suggested by QCD. The method is based on a continuous dialog between experiment and theory. The paper follows the development of this research line, from its beginnings in the seventies to the current state of the art, discussing how it produced both sound interpretations of the most relevant experimental facts and intriguing perspectives for new physics signals in the TeV energy domain.