Instantons in the nonperturbative QCD vacuum

Abstract

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. Dependence of characteristic instanton size on gluon condensate and correlation length in nonperturbative vacuum is found. Comparison of obtained instanton size distribution with lattice data is made.

25 pages, 7 figures, 3 tables, RevTeX4, some corrections made and references added

References in corpus (5)

• Instantons, the QCD Vacuum, and Hadronic Physics
• Confronting Instanton Perturbation Theory with QCD Lattice Results
• Gluon Field Strength Correlation Functions within a Constrained Instanton Model
• Instanton IR stabilization in the nonperturbative confining vacuum
• Abelian Monopole and Center Vortex Views at the Multi-Instanton Gas

Cited by in corpus (1)

• Non-Abelian field strength bilocal correlator at finite temperature in the model of dilute instanton gas