Physical properties of high-temperature QCD matter based on relativistic heavy ion collision reactions

It is six years since Relativistic Heavy Ion Collider (RHIC) of the Brookhaven National Laboratory (BNL) started to operate to explore the completely new extreme state 'Quark-Gluon Plasma' (QGP). Among the enormous results reported, 'Discovery of Perfect Liquid QGP' is the one of the most highlighted results. The motive of the relativistic heavy ion collision physics is to understand the QGP on the basis of experiments as a many-body system of finite temperature and density in QCD. We cannot help but rely upon phenomenological analyses to cope with the results since perturbation theory is no more valid in this temperature scale. In this review, the dynamics of heavy ion collisions and transport properties of the QGP are picked up concerning the topics related to the above mentioned 'discovery'. In section 2, an overview of the heavy ion collisions is given from the viewpoint of the basic physical quantities. In section 3, a brief description of the elliptical flow is described. In section 4, the theoretical analysis of the elliptical flow based on the fluid mechanical description of QGP elaborated by the authors' group is presented. In section 5, the unifying model to describe the overall heavy ion collision is discussed and a perspective including Large Hadron Collider (LHC) is given based on the unifying model. In section 6, a short summary is given. (S. Funahashi)