Rapidity evolution of the gluon helicity at small-x

I’ll discuss evolution of the small-x gluon helicity operator in the rapidity factorization approach. The operator, which is constructed from a polarized Wilson line with one non-eikonal local operator insertion, gives rise to helicity TMDs at small x. To obtain the evolution equation I employ the background field method and derive the form of the leading sub-eikonal correction to the gluon propagator in the background-Feynman gauge. In the end I’ll discuss relation to the large-x polarized DGLAP evolution.