Study of collective matter flow in central C-Ne and C-Cu collisions at 3.7 GeV/nucleon

The transverse momentum technique is used to analyse charged particle exclusive data in the central C-Ne and C-Cu interactions at the energy of 3.7 Gev per nucleon. Clear evidence of in-plane and out-of-plane (squeeze-out) flow effects for protons and π− mesons have been obtained. In C-Ne interactions in-plane flow of π− mesons is in the same direction as for the protons, while in C-Cu collisions pions show antiflow behaviour. From the transverse momentum and azimuthal distributions of protons and π− mesons with respect to the reaction plane, the flow F (the measure of the collective transverse momentum transfer in the reaction plane) and the parameter a2 (the measure of the anisotropic emission strength) have been extracted. The flow effects increase with the mass of the particle and the mass number of target AT. The comparison of our in-plane flow results with flow data for various projectile/target configurations was made using the scaled flow FS=F/(AP1/3+AT1/3). FS demonstrates a common scaling behaviour for flow values from different systems.