Chiral topology of the QCD vacuum in the zero modes enhancement quantum model

Using the trace anomaly relation, low-energy theorem and Witten-Veneziano f ormula for the mass of eta' meson, the chiral topology of the QCD vacuum is numerically evaluated within recently proposed zero modes enhancement quan tum model. It is based on the existence and importance of such kind of the nonperturbative, topologically nontrivial quantum excitations of the gluon field configurations which can be effectively correctly described by the q( -4)-type behaviour of the full gluon propagator in the deep infrared domain . It allows one to calculate the vacuum energy density from first principle s using the effective potential approach for composite operators. We have o btained good agreement with the phenomenological values of the topological susceptibility, the mass of eta' meson, the gluon condensate. An excellent agreement with phenomenological values of the above mentioned quantities is achieved by simply summing up our contribution and instanton-induced contr ibution to the total vacuum energy density.