Flavour Equilibration in Quark-Gluon Plasma

Within the framework of a dynamical and physically transparent model devel-oped earlier, we study the time evolution of various quark flavours in the baryon-free region in ultrarelativistic heavy ion collisions. We show that even under optimistic conditions, the quark-gluon system fails to achieve chemical equilibrium. Quantum Chromodynamics (QCD), the standard theory of strong interactions, predicts that at very high temperature and/or density, the colourless hadronic matter dissolves into its coloured constituents, the quarks and gluons, such that the bulk properties of strongly interacting matter are governed by these degrees of free-dom. Such a locally colour-deconfined phase of matter is known as Quark Gluon Plasma (QGP). It is expected that the temperature and density achievable in ultrarelativistic collisions of heavy ions is favourable for QGP formation, although transiently.