Disoriented Chiral Condensates

The possibility of producing quark-gluon plasma in relativistic heavy ion collisions is an exciting one, especially from the point of view of observing the chiral phase transition as the hot plasma expands and cools. As the system returns to normal phase it is possible for regions of misaligned vacuum to be produced. These domains which are analogous to misaligned domains of a ferromagnet have been named Disoriented Chiral Condensates (DCCs). If we parametrize the condensate using the chiral field $(\sigma,\pi_{i})$ which in the ground state takes the value (v,0), the DCC's are regions where the chiral field is partially aligned in the pion directions. These domains could behave as ``pion lasers'' and emit pions and therefore we will probably be able to detect them. A great amount of recent work is devoted to the study of DCC's, since a better understanding of the relevant physics could shed some light on the most general problem of the QCD phase transition.