Calculating the gauge-invariant two-point correlation function of gluonic field strengths

Abstract

The two-point gauge-invariant correlation function of gluonic field strengths, which is the main input in the stochastic vacuum model, is derived by using its relation to the Green functions of one- and two-gluon gluelumps. These Green functions are found by evaluating the path integrals of one and two gluons confined in the field of an infinitely heavy adjoint source. This allows one to obtain also the terms in the exponential asymptotics of the two-point correlation function, which are produced by fluctuations of the gluons around their mean separation from the source. The pre-exponents are derived as well, demonstrating some novel dependences on the distance.