Instanton infra-red stabilization in the nonperturbative QCD vacuum


Abstract in English

The influence of nonperturbative fields on instantons in quantum chromodynamics is studied. Nonperturbative vacuum is described in terms of nonlocal gauge invariant vacuum averages of gluon field strength. Effective action for instanton is derived in bilocal approximation and it is demonstrated that stochastic background gluon fields are responsible for infra-red (IR)stabilization of instantons. Comparison of obtained instanton size distribution with lattice data is made.

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