Relativistic heavy ion physics and the Relativistic Heavy Ion Collider

Formation of a quark-gluon plasma, a deconfined state of quarks and gluons, is the major focus of relativistic heavy ion experiments at higher energies. For this purpose the Relativistic Heavy Ion Collider (RHIC) and associated experiments are presently under construction at Brookhaven for operation in 1999, and operation with heavy ions is also being planned for the LHC at CERN in 2005. The anticipated temperature and density trajectories at RHIC (and for LHC heavy ions) are expected to lie close to that of the early universe, while those at the AGS and SPS occur at higher baryon densities. A quark-hadron phase transition is predicted to have occurred at around ten micro- seconds after the Big Bang when the universe was at a temperature of approximately 150 to 200 MeV. We discuss the role of the RHIC in these studies. (137 refs)