On the vacuum in multicolor QCD

We assume that among asymptotic solutions to the Makeenko-Migdal equation of the form exp(-aA -bL) (A = area, L = perimeter, A and L large) there is also the solution which has asymptotic freedom at small distances. It is then shown that the vacuum is filled with magnetic vortex lines with non-trivial topology. The vacuum energy is calculated, and we find that it is exponentially small for large volumes. The Higgs phase is then ruled out, b = 0. Our result for the vacuum energy agrees well with an expression obtained by 't Hooft from duality. (orig.)