Gauge invariance of transverse momentum dependent distributions at small x

The interplay between the small-x limit of QCD amplitudes and QCD factorization at moderate x has been studied extensively in recent years. It was finally shown that semiclassical formulations of small-x physics can have the form of an infinite twist framework involving transverse momentum dependent distributions in the eikonal limit. In this work, we demonstrate that small-x distributions can be formulated in terms of transverse gauge links. This allows, in particular, for direct and efficient decompositions of observables into subamplitudes involving gauge-invariant suboperators which span parton distributions.