Large-scale structure of the deconfined phase

Quantum chromodynamics at finite temperature and chemical potential is investigated nonperturbatively at large distance scales in terms of its three-dimensional effective theory, which for the gauge group SU(2) is the Georgi-Glashow-Polyakov model. It is shown that a global SU(2) symmetry breaks if the temperature is high enough and it is argued that this new transition most likely coincides with deconfinement. Some implications for quark-gluon-plasma physics are discussed.