Parton distribution function for the gluon condensate

Motivated by the desire to understand the nucleon mass structure in terms of light-cone distributions, we introduce the twist-four parton distribution function F(x) whose first moment is the gluon condensate in the nucleon. We present the equation of motion relations for F(x) and discuss the possible existence of the delta function (zero mode) contribution at x = 0. We also perform one-loop calculations for quark and gluon targets.