SEARCH FOR POLARIZED INSTANTONS IN THE VACUUM

The new phase of a gauge theory in which the instantons are ''polarize d,'' i.e., have the preferred orientation, is discussed. A class of ga uge theories with the specific condensates of the scalar fields is con sidered. In these models there exists an interaction between instanton s resulting from one-fermion loop corrections. The interaction makes t he identical orientation of instantons the most probable, permitting o ne to expect the system to undergo a phase transition into the state w ith polarized instantons. The existence of this phase is confirmed in the mean-field approximation in which then is a first-order phase tran sition separating the ''polarized phase'' from the usual nonpolarized one. The considered phase can be important for the description of grav ity in the framework of the gauge field theory.