QCD, the theory of strongly interacting matter, predics that, above
a critical energy density, hadrons, the constituents or normal nuclear matter,
decompose into a plasma of quarks and gluons, the Quark Gluon Plasma, QGP.
Such a state existed
shortly after the Big Bang
and may exist as well in the neutron stars.
Colliding heavy ions at extreme energies is the only way to
study QGP on Earth.
The phase diagram of nuclear matter
History of the Universe poster
picture from
CERN QGP press release
A. Andronic
Last modified: Tue Jan 30 18:58:53 CET 2007