Operator product expansion and confinement

Abstract

The operator product expansion (OPE) technique is analyzed in Abelian and non-Abelian field theoretical models with confinement. Special attention is paid to the regimes where the nonzero virtuality of vacuum fields is felt by external currents. It is stressed that despite the fact that the physics of confinement is sometimes considered as being caused by ``soft'' fields, it can exhibit pronounced ``hard'' effects in OPE.