Anisotropic (v₁ and v₂) Flow in Relativistic Heavy-Ion Collisions at Energies between 4 GeV and 200 GeV

¹ Department of Physics, University of Oslo, PB 1048 Blindern, N-0316 Oslo, Norway
² Taras Shevchenko National University of Kyiv, UA-01033 Kyiv, Ukraine
³ Skobeltsyn Institute of Nuclear Physics, Moscow State University, RU-119991 Moscow, Russia
⁴ National Research Nuclear University "MEPhI" (Moscow Engineering Physics Institute), RU-115409 Moscow, Russia

^* e-mail: larissa.bravina@fys.uio.no

Published online: 31 October 2018

Abstract

Basic features of directed and elliptic flows of identified hadrons in heavy-ion collisions at intermediate and high energies are considered within two transport string models, UrQMD and QGSM. Both models indicate changing of the sign of proton directed flow at midrapidity from antiflow to normal flow with decreasing energy of collisions. The origin of this effect is traced to hadron rescattering in baryon-rich remnants of the colliding nuclei. To distinguish the effect of rescattering from the flow softening caused by creation of quark-gluon plasma one has to compare heavy-ion and light-ion collisions at the same energy. Both directed and elliptic flows at midrapidity are formed within t = 10-12 fm/c. The differences in the development of elliptic flows of mesons and baryons are found at high energies. These differences can be explained by dissimilar freeze-out conditions, thus suggesting simultaneous study of particle collective flow and freeze-out.