Perturbative renormalization of quasi-parton distribution functions

TLDR: In this paper, the renormalization of gauge invariant nonlocal fermion operators which contain a Wilson line, to one-loop level in lattice perturbation theory is presented.

Abstract: In this paper we present results for the renormalization of gauge invariant nonlocal fermion operators which contain a Wilson line, to one-loop level in lattice perturbation theory Our calculations have been performed for Wilson/clover fermions and a wide class of Symanzik improved gluon actions The extended nature of such ``long-link'' operators results in a nontrivial renormalization, including contributions which diverge linearly as well as logarithmically with the lattice spacing, along with additional finite factors On the lattice there is also mixing among certain subsets of these nonlocal operators; we calculate the corresponding finite mixing coefficients, which are necessary in order to disentangle individual matrix elements for each operator from lattice simulation data Finally, extending our perturbative setup, we present nonperturbative prescriptions to extract the linearly divergent contributions