Various flows of black and grey particles produced in Mg-emulsion collisions at 4.5 A GeV c

Abstract: Various flow phenomena of black particles (b-particles) and grey particles (g-particles) produced in magnesium-emulsion (Mg-Em) collisions at 4.5 A GeV /c are reported. These flows are directed and elliptic transverse flows (v₁ and v₂) related by the azimuthal angle (φ), directed and elliptic reaction plane flows (v_R1 and v_R2) related by the projected angle (ψ) on the reaction plane, and directed and elliptic polar direction flows (v_P1 and v_P2) related by the polar angle (θ). We extract absolute flows as the direct experimental values minus the isotropic theoretical values. The dependence of the various flows on the target particle multiplicity and on the angles (θ,φ,ψ) is investigated. Our results show that the dependence of b-particle flows on the target size is obvious and for heavy targets the dependence on target particle multiplicity is slight. Compared with b-particles, g-particles have a slight dependence on the target size and target particle multiplicity.