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arXiv · 2305.05212

Leading Power Accuracy in Lattice Calculations of Parton Distributions

Rui Zhang·Jack Holligan·Xiangdong Ji·Yushan Su
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Abstract

In lattice-QCD calculations of parton distribution functions (PDFs) via large-momentum effective theory, the leading power (twist-three) correction appears as ${\cal O}(\Lambda_{\rm QCD}/P^z)$ due to the linear-divergent self-energy of Wilson line in quasi-PDF operators. For lattice data with hadron momentum $P^z$ of a few GeV, this correction is dominant in matching, as large as 30\% or more. We show how to eliminate this uncertainty through choosing the mass renormalization parameter consistently with the resummation scheme of the infrared-renormalon series in perturbative matching coefficients. An example on the lattice pion PDF data at $P^z = 1.9$ GeV shows an improvement of matching accuracy by a factor of more than $3\sim 5$ in the expansion region $x= 0.2\sim 0.5$.

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Rui Zhang, Jack Holligan, Xiangdong Ji, Yushan Su. 2023-05-09. Leading Power Accuracy in Lattice Calculations of Parton Distributions. https://doi.org/10.1016/j.physletb.2023.138081

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