Signals of quark�gluon plasma

Abstract

Relativistic heavy ion collision is a fascinating field of research. In recent years, the field has seen an unprecedented level of progress. A new state of matter, deconfined quark–gluon plasma (QGP), was predicted. An accelerator was built to detect this new state of matter. Experiments were performed and the discovery of the 'most perfect fluid' was made. Conclusive identification of the most perfect fluid state with the deconfined state has yet to be achieved. One of the impediments towards such identification is the fundamental property of the strong interaction, the 'color confinement', i.e. the constituents of the theory, the 'colored' quarks and gluons, are confined within a hadron. Any information about the deconfined state must be amassed from the color-neutral hadrons. And yet the process by which colored building blocks convert into a color singlet state is not properly understood. This necessitates model building. To young researchers, the field poses a problem in that it is multi-disciplinary, requiring knowledge of thermodynamics, statistical physics, kinetic theory, group theory, quantum chromodynamics (QCD), etc. The complexity of heavy ion collisions has necessarily led to a proliferation of models, e.g. the thermal model, blast wave model hydrodynamic model and models based on transport equations, etc, the physics of which need to be understood.