Corrélation multiparticulaire et intermittence dans des collisions de hautes énérgies

The analysis of the intermittency signal observed in high energy experiments is presented using multiparticle distributions and correlation functions. The effect of the dimensional projection of the multiparticle distributions on one or two-dimensional subspace is discussed. The structure of the multiparticle cumulants is analyzed for the DELPHI e+e- annihilation data. The model of spatiotemporal intermittency is discussed in details and is shown to reproduce qualitatively the dependence of the intermittency strength on the target and projectile nuclei. A 1-dimensional (1D) cellular-automaton and a 1D forest-fire model is studied. On the example of the noncritical 1D Ising model the difficulties of the scaled factorial moment (SFM) method in extracting genuine scaling behaviour is illustrated. All these studies could serve as tools to test the sensibility of the SFM method as used in the analysis of the high energy production.Dans ce travail, l'analyse du signal d'intermittence observé dans des expériences de haute énergie est présentée en utilisant des distributions spatiales et des fonctions de corrélations