DECONFINEMENT IN QCD WITH DYNAMICAL QUARKS

We study the phase structure of full QCD within the canonical ensemble (CE) with respect to triality in a lattice formulation. The procedure to calculate the effective potentials (EP) in the CE is given. We cal culate the EP for the three-dimensional SU(2) gauge model at finite te mperature in the strong coupling region. The potential exhibits a genu ine deconfinement phase transition unlike the similar potential obtain ed in the grand canonical ensemble (GCE). Furthermore, we investigate the EP with the chiral condensate included. Contrary to other recent r esults we find chiral symmetry restoration in all triality sectors. De aling with massless staggered fermions we observe chiral symmetry rest oration accompanying a deconfinement phase transition of first-order. Above the critical point, besides two 2(2) symmetric ''deconfining'' v acua there exists a metastable ''confining'' vacuum in a wide region o f the (N-t,N-gamma)-plane. Such a picture could be interpreted as an i ndication for a mixed state of hadrons and quarks in the vicinity of t he critical line.