Search for "polarized" instantons in the vacuum.

Abstract

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 correction. The interaction makes the identical orientation of instantons to be the most probable, permitting one to expect the system to undergo the phase transition into the state with polarized instantons. The existence of this phase is confirmed in the mean-field approximation in which there is the first order phase transition separating the ``polarized phase'' from the usual non-polarized one. The considered phase can be important for the description of gravity in the framework of the gauge field theory.