Threshold resummation for computing large-x parton distribution through large-momentum effective theory

A bstract Parton distribution functions (PDFs) at large x are poorly constrained by high-energy experimental data, but extremely important for probing physics beyond standard model colliders. We study the calculation of PDFs large- through large-momentum P z expansion lattice quasi PDFs. Similar to deep-inelastic scattering, there two distinct perturbative scales in threshold limit where matching coefficient can be factorized into a space-like jet function scale |1 − y| and pair heavy-light Sudakov form factors . The formula allows us derive full renormalization group resummation logarithms, result is consistent with known next-to-next leading order (NNLO). This paves way direct calculations QCD. As by-products, we find that related time-like version calculated previously analytic continuation, factor, here NNLO, universal object appearing as well momentum transverse-momentum-dependent wave-function amplitudes.