Parton distribution function for topological charge at one loop

Abstract

Abstract We present results for the gg-part of the one-loop corrections to the recently introduced “topological charge” GPD $$ \overset{\sim }{F} $$ F ~ (x, q2). In particular, we give expression for 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” δ(x) terms were found for the twist-4 gluon GPD $$ \overset{\sim }{F} $$ F ~ (x, q2).