From a white to a coloured world : Quark-Gluon Plasma within a quasiparticle approach

Quarks and gluons are part of the most fundamental particles known up to now. They are bound inside structures that are called hadrons (as the proton or the neutron) and interact together thanks to the strong interaction. These particles have some remarkable properties. For instance, they can not be observed as free particles: Quarks and gluons are always confined inside the hadrons. In the manner of the electromagnetism that allows two charge states (+ or -), quarks and gluons can be describe with six charge states that physicists call poetically « colour » (red, blue, green, anti-red, anti-blue, anti-green). Because of the confinement, only white composite particles can be observed.
Nevertheless, by increasing the temperature, one can reach a new state of matter called Quark-Gluon Plasma (QGP). This state of matter is characterized by the fact that quarks and gluons can move quasi-freely inside this medium. Coloured charges are thus revealed.
Understanding the mechanism driving this transition is a fascinating topic nowadays since experiments as RHIC (Brookaven, USA) and LHC (CERN, Europe) have pointed out some evidences of the QGP existence. In this seminar, we will present a quasiparticle approach in order to describe this new state of matter. Such kind of approaches have the advantage of giving us a picture of what happens by trying to isolate the main phenomena characterizing the state. We will mostly focus on the description of the pure gauge sector (only a plasma with gluons).