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

Directed (in-plane) flows of protons, pions, and projectile light fragments (d, t, 3He, 4He) have been observed by investigating the dependence of the mean transverse momentum in the reaction plane 〈px〉 on the rapidity y in the c.m. system for CC collisions at a momentum of 4.2 GeV/c per nucleon. The comparison of our in-plane-flow results of protons 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 behavior for flow values from different systems. From azimuthal distributions of protons and π− mesons, out-of-plane (squeeze-out) flow effects have been observed and the parameter a2 (the measure of the anisotropic emission strength) has been extracted. The quark-gluon string model reproduces the experimental results quite well.