Search for ``polarized'' instantons in the vacuum

The new phase of a gauge theory in which the instantons are ``polarized,'' i.e., have the preferred orientation, is discussed. A class of gauge theories with the specific condensates of the scalar fields is considered. In these models there exists an interaction between instantons resulting from one-fermion loop corrections. The interaction makes the identical orientation of instantons the most probable, permitting one to expect the system to undergo a phase transition into the state with polarized instantons. The existence of this phase is confirmed in the mean-field approximation in which there is a first-order phase transition separating the ``polarized phase'' from the usual nonpolarized one. The considered phase can be important for the description of gravity in the framework of the gauge field theory.