On the dynamics of the nucleus-nucleus collisions at 4.5 A GeV/c involving relative small number of participants

There is no satisfactory study in the literature for the nucleus-nucleus collisions in the range of the intermediate energies between 2 A GeV and 10 A GeV, especially for the nuclear partners including a relative small number of participants. This paper is devoted to an experimental and phenomenological analysis of such a process at 4.5 A GeV with He and C nuclei as projectiles and a number of different targets (from Li to Pb). The study is based on a number of about 14000 events collected by the SKM200 spectrometer, with streamer chamber, from the JINR Dubna (Russia). The aim of the study is to find the dynamics existing for a relative small number of participants (nuclear flow, thermodynamic features). The unusual behaviour associated with the local fluctuations of the nuclear density (the signatures of nuclear jets, the cumulative effect, the shock wave, the production of dibaryons) are studied, too. (authors)