JUST ONE MORE APPROACH TO CALCULATING THE QCD GROUND STATE

The quark behaviour in the background of intensive stochastic gluon field is studied. An approximate procedure for calculating the effective Hamiltonian is developed and the corresponding ground state within the HartreeFock-Bogolyubov approach is found. The comparative analysis of various model Hamiltonian is given and transition to the chiral limit in the Keldysh model is discused in detail. We study response to the process of filling up the Fermi sphere with quarks, calculate the vacuum pressure and demonstrate the existence of filled-in state degenerate with the vacuum one. We study the quark (anti-quark) behaviour while being influenced by intensive stochastic gluon field and work in the context of the Euclidean field theory. The corresponding Lagrangian density is the following