Study of collective flow effects in CC-collisions at a momentum of 4.2 GeV/c per nucleon

Abstract

The directed (in-plane) flows of protons, pions and projectile light fragments (d, t, sup 3 He, sup 4 He) have been observed by investigating the dependence of the mean transverse momentum in the reaction plane on the rapidity in the center-of-mass system. The comparison of our in-plane flow results of protons with flow data for various projectile/target configurations was made using the scaled flow F sub s = F/(A sub p sup 1 sup / sup 3 + A sub t sup 1 sup / sup 3). F sub s demonstrates a common scaling behaviour for flow values from different systems. From azimuthal distributions of protons and pi sup - mesons the out-of-plane (squeeze-out) flow effects have been observed and the parameter a sub 2 (the measure of the anisotropic emission strength) has been extracted. The Quark-Gluon String Model reproduces quite well the experimental result