Quark – Gluon Plasma

Quark – Gluon Plasma

The QGP is a state of matter wherein quarks and gluons are no longer confined in hadrons.  Such a state is predicted by the current theory of the strong interaction (called quantum chromodynamics, QCD) for very high temperatures and very high densities.  The transition between confined matter and the QGP would occur when the temperature exceeds a critical value estimated to be around 2000 billion degrees (about 100 000 times the temperature of the core of the Sun). Such extreme temperatures have not existed in Nature since the birth of the Universe: it is believed that for a few millionths of a second after the Big Bang the temperature was above the critical value, and the entire Universe was in a quark-gluon plasma state.