Speaker
Description
We present the results for the one-loop corrections to the "gluon condensate" twist-4 PDF F(x), in particular, we give expression for the $gg$-part of its evolution kernel. To enforce strict compliance with the gauge invariance requirements, we have used on-shell states for external gluons and have obtained identical results both in Feynman and light-cone gauges. No "zero mode" terms were found for $F(x)$. However, a $q^2 \delta (x)$ term was found for the $\xi=0$ GPD $F(x,q^2)$ at nonzero momentum transfer $q$. These results do not agree with the original attempt of one-loop calculations of $F(x)$ for gluon states, which sets alarm warning for calculations and the lattice renormalization procedures that use matrix elements with virtual external gluons.
