Coherency vs. Stochasticity in Spike Production in Nuclear Collisions at Intermediate Energies

Multiparticle spike-production process is investigated in central C-Cu collisions at 4.5 $A$ Gev/c per nucleon. The study is based on two different hypotheses - stochastic vs. coherent - of the formation of spikes. To observe manifestations of the stochastic dynamics, the non-regularities in the multiplicity distributions are analyzed using intermittency approach to a possible phase transition as well as the one-dimensional intermittency model. The entropy indices are calculated based on the erraticity approach. Coherency is studied in the framework of the coherent gluon-jet radiation model. To this end, the spike-center pseudorapidity distributions are analyzed. Coexistence of the two mechanisms of spike formation process is discussed.