Confinement, instanton-dyons and monopoles

Confinement in QCD vacuum has been traditionally explained in terms of monopoles, and now quark-gluon plasma produced in heavy ion collisions is described as a dual plasma containing as quasiparticles not only quarks and gluons but also magnetic monopoles, dominating the ensemble near T_c. Chiral symmetry breaking was traditionally described in terms of instantons. At finite temperatures the nonzero Polyakov line VEV splits them into instanton-dyons. The semiclassical ensemble of those was shown to describe well both the deconfinement and chiral phase transitions. Furthermore, the semiclassical theory describes multiple phase transitions of Roberge-Weiss type, when periodicity phases of fermions cross the holonomy phases. The interrelation of monopoles and instanton-dyons is explained in terms of the so called Poisson duality between them: both describe the same nonperturbative phenomena and lead to the same partition function. However the QCD monopoles have action S ∼ log(1/g²) and thus are not classical fields.