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Abstract
The aim of the present work is to study the characteristic features of the shower particles multiplicity in the interactions of 4He beams, from the Dubna Synchrophasteron, with the nuclear emulsion at 2.1 A and 3.7 A GeV. This has been carried out over a wide range of target masses (H,CNO, Em and AgBr ). The observed data in the 4s space have been explained in the forward and backward hemispheres. The multiplicity characteristics have been measured for the total sample events corresponding to the average impact parameters and also the event samples corresponding to different centralities. The results have been simulated according to the Lund Monte Carol event generators using the modified FRITIOF model. The energy and projectile size are the effective parameters, in the forward emitted shower particles production while the target size has an unessential effect. The target size is the only effective parameter, in the backward emitted shower particles production, regarding the nuclear limiting fragmentation. It has been suggested that the pion production, in the forward hemisphere, is a source of hadron matter while the backward emitted one is mainly a decay from an excited target nuclear cluster. On the basis of the nuclear matter size and binary collisions, the selectivity of the centrality parameter has been found successful. According to the centrality the shape of the multiplicity distributions change from a decay shape to bell shape. For a given system size or source, the shape shifs are not necessarily similar