A theoretical overview of relativistic heavy ion collisions and the quark-gluon plasma

About a decade ago, some theorists and experimentalists in both particle physics and nuclear physics came together in Bielefeld, Germany to discuss how the theoretically predicted new state of matter, called quark-gluon plasma (QGP), can be produced and seen in a laboratory. Since then, a lot of theoretical perceptions of this endeavour, and indeed about the QGP itself, have undergone a substantial change. The nucleus-nucleus collision data from CERN, Geneva and BNL, New York have been partly responsible for this. However, the progress in finite temperature lattice quantum chromodynamics (QCD) and the theoretical investigations of formation and detection of QGP have also been very crucial. A brief overview of these recent theoretical developments is presented with special emphasis on a signal of quark-gluon plasma, namely, J/ψ-suppression. (author). 25 refs., 5 figs., 1 tab