Abstract
We present the first lattice QCD calculation of the charm quark contribution to the nucleon electromagnetic form factors GE,Mc(Q2) in the momentum transfer range 0≤Q2≤1.4 GeV2. The quark mass dependence, finite lattice spacing and volume corrections are taken into account simultaneously based on the calculation on three gauge ensembles including one at the physical pion mass. The nonzero value of the charm magnetic moment μMc=−0.00127(38)stat(5)sys, as well as the Pauli form factor, reflects a nontrivial role of the charm sea in the nucleon spin structure. The nonzero GEc(Q2) indicates the existence of a nonvanishing asymmetric charm-anticharm sea in the nucleon. Performing a nonperturbative analysis based on holographic QCD and the generalized Veneziano model, we study the constraints on the [c(x)−c¯(x)] distribution from the lattice QCD results presented here. Our results provide complementary information and motivation for more detailed studies of physical observables that are sensitive to intrinsic charm and for future global analyses of parton distributions including asymmetric charm-anticharm distribution.
Original language | English |
---|---|
Article number | 135633 |
Journal | Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics |
Volume | 808 |
DOIs | |
State | Published - Sep 10 2020 |
Bibliographical note
Publisher Copyright:© 2020 The Author(s)
Funding
RSS thanks Jeremy R. Green, Luka Leskovec, Jian-Wei Qiu, Anatoly V. Radyushkin, and David G. Richards for useful discussions. The authors thank the RBC/UKQCD collaborations for providing their DWF gauge configurations. This work is supported by the U.S. Department of Energy , Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177 . A. Alexandru is supported in part by U.S. DOE Award Number DE-FG02-95ER40907 . T. Draper and K.F. Liu are supported in part by DOE Award Number DE-SC0013065 . Y. Yang is supported by Strategic Priority Research Program of Chinese Academy of Sciences , Grant No. XDC01040100 . This research used 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 . This work used Stampede time under the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation grant number ACI-1053575 . We also thank the National Energy Research Scientific Computing Center (NERSC) for providing HPC resources that have contributed to the research results reported within this paper. 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 . RSS thanks Jeremy R. Green, Luka Leskovec, Jian-Wei Qiu, Anatoly V. Radyushkin, and David G. Richards for useful discussions. The authors thank the RBC/UKQCD collaborations for providing their DWF gauge configurations. This work is supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177. A. Alexandru is supported in part by U.S. DOE Award Number DE-FG02-95ER40907. T. Draper and K.F. Liu are supported in part by DOE Award Number DE-SC0013065. Y. Yang is supported by Strategic Priority Research Program of Chinese Academy of Sciences, Grant No. XDC01040100. This research used 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. This work used Stampede time under the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation grant number ACI-1053575. We also thank the National Energy Research Scientific Computing Center (NERSC) for providing HPC resources that have contributed to the research results reported within this paper. 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.
Funders | Funder number |
---|---|
National Energy Research Scientific Computing Center | |
DOE Office of Nuclear Physics | |
National Science Foundation Arctic Social Science Program | ACI-1053575 |
National Science Foundation Arctic Social Science Program | |
U.S. Department of Energy EPSCoR | DE-FG02-95ER40907, DE-SC0013065 |
U.S. Department of Energy EPSCoR | |
Directorate for Computer and Information Science and Engineering | 1053575 |
Directorate for Computer and Information Science and Engineering | |
Office of Science Programs | |
Institute for Nuclear Physics | DE-AC05-06OR23177 |
Institute for Nuclear Physics | |
Chinese Academy of Sciences | DE-AC05-00OR22725, XDC01040100 |
Chinese Academy of Sciences |
Keywords
- Form factor
- Intrinsic charm
- Lattice QCD
- Light-front holographic QCD
- Parton distributions
ASJC Scopus subject areas
- Nuclear and High Energy Physics