We present the first lattice-QCD calculation of the nucleon isovector unpolarized parton distribution functions (PDFs) at the physical-continuum limit using Large-Momentum Effective Theory (LaMET). The lattice results are calculated using ensembles with multiple sea pion masses with the lightest one around 135~MeV, 3 lattice spacings a∈[0.06,0.12]~fm, and multiple volumes with MπL ranging 3.3 to 5.5. We perform a simultaneous chiral-continuum extrapolation to obtain RI/MOM renormalized nucleon matrix elements with various Wilson-link displacements in the continuum limit at physical pion mass. Then, we apply one-loop perturbative matching to the quasi-PDFs to obtain the lightcone PDFs. We find the lattice-spacing dependence to be much larger than the dependence on pion mass and lattice volume for these LaMET matrix elements. Our physical-continuum limit unpolarized isovector nucleon PDFs are found to be consistent with global-PDF results.
@article{arxiv.2011.14971,
title = {Lattice Nucleon Isovector Unpolarized Parton Distribution in the Physical-Continuum Limit},
author = {Huey-Wen Lin and Jiunn-Wei Chen and Rui Zhang},
journal= {arXiv preprint arXiv:2011.14971},
year = {2020}
}