Peculiarities of secondary particle generation process in Pb-Pb interactions at 158A GeV

Experimental data on Pb-Pb central collisions were obtained by means of emulsion magnetic chambers containing the lead target irradiated with the Pb beam in the magnetic field of 1.8 Tesla at CERN in December, 1994 and November, 1996. 50 μm thick emulsion layers were placed perpendicular to the beam. Results of data analysis show existence of certain peculiar patterns in several central collisions (e.g. ring-like events, jets, multiple narrow spikes in secondary particle pseudorapidity distributions, etc.) The methods of pattern recognition theory, in particular, wavelet technique (the method of localized spectral analysis), used in target diagram analysis, reveal the detailed features of such structures.