MODELING OF HEAVY-ION COLLISIONS AT THE RELATIVISTIC HEAVY-ION COLLIDER

Abstract

The first five years of RHIC operations at √ sNN = 130 GeV and √ sNN = 200 GeV have yielded a vast amount of interesting and sometimes surprising results , many of which have not yet been fully evaluated or understood by theory. There exists mounting evidence that RHIC has created a hot and dense state of deconfined QCD matter with properties similar to that of an ideal fluid 5,6 – this state of matter has been termed the strongly interacting Quark-Gluon-Plasma (sQGP). The current level of understanding of the RHIC data has been summarized in a series of publications which appeared in two special volumes of Nuclear Physics A: the first one outlining the current theoretical views and case for the sQGP 7 and the second one detailing the experimental results of the first three years of RHIC operations . Heavy-Ion collisions at RHIC involve several distinct reaction stages, starting from the two initial ground states of the colliding nuclei, followed by the high density phase in which a plasma may form, up to the final freeze-out of hadrons. The central problem in the study of the QGP is that the deconfined quanta of a QGP are not directly observable due to the fundamental confining property of the physical QCD vacuum. If we could see free quarks and gluons (as in ordinary plasmas) it would be trivial to verify the QCD prediction of the QGP state. However, nature chooses to hide those constituents within the confines of color neutral composite many body systems – hadrons. One of the main tasks in relativistic heavy-ion research is to find clear and unambiguous connections between the tran-