Speaker
Description
In lattice-QCD calculations of parton distribution functions (PDFs) via large-momentum effective theory, the leading power correction appears as ${\cal O}(\Lambda_{\rm QCD}/P^z)$ in matching to the quasi distributions due to linearly-divergent self-energy in quasi-PDF operators. For lattice data with hadron momentum $P^z$ of a few GeV, this correction is important for accurate predictions of the effective theory. We show how to attain the leading power accuracy by fixing the scheme of non-perturbative mass renormalization in the quasi-PDFs consistent with the summation/regularization method of the infrared-renormalon series in the matching coefficients. A demonstrative example on the pion PDF data at $P^z = 1.9$ GeV is shown to improve the theoretical error in matching by a factor of $3$ in the region $x= 0.2\sim 0.5$.
