Abstract
We extract the pion valence quark distribution qvπ(x) from lattice QCD (LQCD) calculated matrix elements of spacelike correlations of one vector and one axial vector current analyzed in terms of QCD collinear factorization, using a new short-distance matching coefficient calculated to one-loop accuracy. We derive the Ioffe time distribution of the two-current correlations in the physical limit by investigating the finite lattice spacing, volume, quark mass, and higher-twist dependencies in a simultaneous fit of matrix elements computed on four gauge ensembles. We find remarkable consistency between our extracted qvπ(x) and that obtained from experimental data across the entire x range. Further, we demonstrate that the one-loop matching coefficient relating the LQCD matrix computed in position space to the qvπ(x) in momentum space has well-controlled behavior with Ioffe time. This justifies that LQCD-calculated current-current correlations are good observables for extracting partonic structures by using QCD factorization, which complements to the global effort to extract partonic structure from experimental data.
Original language | English |
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Article number | 054508 |
Journal | Physical Review D |
Volume | 102 |
Issue number | 5 |
DOIs | |
State | Published - Sep 2020 |
Externally published | Yes |
Funding
We thank Carl Carlson, Martha Constantinou, Luka Leskovec, Tianbo Liu, Wayne Morris, Anatoly Radyushkin, Nobuo Sato, and Jian-Hui Zhang who provided insights and expertise that greatly assisted this research. This work is supported by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 within the framework of the TMD Collaboration. We acknowledge the facilities of the USQCD Collaboration used for this research in part, which are funded by the Office of Science of the U.S. Department of Energy. This material is based in part upon work supported by a grant from the Southeastern Universities Research Association (SURA) under an appropriation from the Commonwealth of Virginia. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation Grant No. ACI-1548562 , and the Texas Advanced Computing Center (TACC) at the University of Texas at Austin for providing HPC resources on Frontera that have contributed to the results in this paper. This work was performed in part using computing facilities at William and Mary which were provided by contributions from the National Science Foundation (MRI Grant No. PHY-1626177), the Commonwealth of Virginia Equipment Trust Fund and the Office of Naval Research. In addition, this work used resources at National Energy Research Scientific Computing Center (NERSC), a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231, as well as resources of the Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05-00OR22725 (ALCC Project No. NPH134). The configurations used in this work were generated under INCITE. The software codes chroma , quda and qp hi x were used. The authors acknowledge support from the U.S. Department of Energy, Office of Science, Office of Advanced Scientific Computing Research and Office of Nuclear Physics, Scientific Discovery through Advanced Computing (SciDAC) program. Also acknowledged is support from the U.S. Department of Energy Exascale Computing Project. C. E. is supported in part by the U.S. Department of Energy under Contract No. DE-FG02-04ER41302 and a Department of Energy Office of Science Graduate Student Research fellowship, through the U.S. Department of Energy, Office of Science, Office of Workforce Development for Teachers and Scientists, Office of Science Graduate Student Research (SCGSR) program. Y. M. is supported in part by the National Natural Science Foundation of China under Grants No. 11875071 and No. 11975029. K. O. acknowledges support in part by the U.S. Department of Energy through Grant No. DE-FG02-04ER41302, by STFC consolidated Grant No. ST/P000681/1.