Determination of the reaction plane and collective flow in nucleus-nucleus interactions at 4.5 a GeV/c

Nuclear emulsions are used to investigate spallations produced by 4.5 A GeV/c Mg-24 and Si-28 nuclei. The integral multiplicity distribution of disintegrated particles from target nuclei is used to separate the inelastic interactions with the free hydrogen (H), the light (CNO), and the heavy (AgBr) nuclei. Angle of flow, transverse momentum, angular characteristics, and azimuthal alignment data are analyzed for the presence collective fragments in Mg-24 + Ag(Br) and Si-28 + Ag(Br) collisions with emulsion nuclei at 4.5 A GeV/c. The determination of the reaction plane is powerful tool for investigating the nucleus-nucleus interactions. The analysis of the projection of the transverse momentum, angular characteristics, azimuthal alignment and range onto the reaction plane shows a significant side splash of the target fragment.