# Improving the Precision of First-Principles Calculation of Parton Physics from Lattice Quantum Chromodynamics

## TL;DR

This paper discusses how lattice quantum chromodynamics can be used to improve the precision of calculations related to the internal structure of protons.

## Contribution

The paper introduces new lattice renormalization and matching techniques that enhance the accuracy of parton distribution predictions.

## Key findings

- Hybrid renormalization schemes and improved matching kernels increase the accuracy of LaMET predictions.
- The Coulomb-gauge correlator approach improves precision in transverse-momentum-dependent structures.
- New lattice interpolation operators promise higher proton momenta and better signal-to-noise ratios.

## Abstract

Large momentum effective theory (LaMET) provides a general framework for computing the multi-dimensional partonic structure of the proton from first principles using lattice quantum chromodynamics (QCD). In this effective field theory approach, LaMET predicts parton distributions through a power expansion and perturbative matching of a class of Euclidean observables—quasi-distributions—evaluated at large proton momenta. Recent advances in lattice renormalization, such as the hybrid scheme with leading renormalon resummation, together with improved matching kernel that incorporates higher-loop corrections and resummations, have enhanced both the perturbative and power accuracy of LaMET, enabling a reliable quantification of theoretical uncertainties. Moreover, the Coulomb-gauge correlator approach further simplifies lattice analyses and improves the precision of transverse-momentum-dependent structures, particularly in the non-perturbative region. State-of-the-art LaMET calculations have already yielded certain parton observables with important phenomenological impact. In addition, the recently proposed kinematically enhanced lattice interpolation operators promise access to unprecedented proton momenta with greatly improved signal-to-noise ratios, which will extend the range of LaMET prediction and further suppress the power corrections. The remaining challenges, such as controlling excited-state contamination in lattice matrix elements and extracting gluonic distributions, are expected to benefit from emerging lattice techniques for ground-state isolation and noise reduction. Thus, lattice QCD studies of parton physics have entered an exciting stage of precision control and systematic improvement, which will have a broader impact for nuclear and particle experiments.