Condensate preserving the symmetry of the Lagrangian. Symmetry breakdown

A multicomponent scalar field may preserve the symmetry of the Lagrangian when the stability of the perturbation theory vacuum is lost. This leads to the appearance of a degenerate vacuum, whose excitation spectrum slightly differs from the spectrum observed in the case of spontaneous symmetry breaking. The possibility of the appearance of such a condensate in a QCD vacuum is discussed.