Unpolarized and Helicity Generalized Parton Distributions of the Proton within Lattice QCD
Abstract
We present the first calculation of the x dependence of the proton generalized parton distributions (GPDs) within lattice QCD. Results are obtained for the isovector unpolarized and helicity GPDs. We compute the appropriate matrix elements of fast-moving protons coupled to nonlocal operators containing a Wilson line. We present results for proton momenta 0.83,1.25,1.67 GeV, and momentum transfer squared 0.69,1.38 GeV2 . These combinations include cases with zero and nonzero skewness. The calculation is performed using one ensemble of two degenerate mass light quarks, a strange quark, and a charm quark of maximally twisted mass fermions with a clover term. The lattice results are matched to the light-cone GPDs using one-loop perturbation theory within the framework of large momentum effective theory. The final GPDs are given in the MS ¯ scheme at a scale of 2 GeV.
- Publication:
-
Physical Review Letters
- Pub Date:
- December 2020
- DOI:
- 10.1103/PhysRevLett.125.262001
- arXiv:
- arXiv:2008.10573
- Bibcode:
- 2020PhRvL.125z2001A
- Keywords:
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- High Energy Physics - Lattice;
- High Energy Physics - Experiment;
- High Energy Physics - Phenomenology;
- High Energy Physics - Theory
- E-Print:
- Main document: 5 pages, Supplementary document (Appendix): 10 pages. Version accepted for publication in Physical Review Letters