Effective string rope model for the initial stages of ultra-relativistic heavy ion collisions

Abstract

Different approaches to describe initial stages of relativistic heavy ion collisions are discussed qualitatively and quantitatively. An effective string rope model is presented for heavy ion collisions at RHIC energies. Our model takes into account baryon recoil for both target and projectile, arising from the acceleration of partons in an effective field, F μν , produced in the collision. The typical field strength (string tension) for RHIC energies is about 5–12 GeV /fm, what allows us to talk about “string ropes”. The results show that a QGP forms a tilted disk, such that the direction of the largest pressure gradient stays in the reaction plane, but deviates from both the beam and the usual transverse flow directions. The produced initial state can be used as an initial condition for further hydrodynamical calculations. Such initial conditions lead to the creation of third flow component.