2020/08/31 by Constantia Alexandrou, Krzysztof Cichy, Martha Constantinou +4 · 1 citation
Physics and Astronomy · #hep-lat #hep-ex #hep-ph #hep-th
paper · pdf · doi:10.1103/physrevlett.125.262001
published as Phys. Rev. Lett. 125, 262001 (2020) · Main document: 5 pages, Supplementary document (Appendix): 10 pages. Version accepted for publication in Physical Review Letters
arxiv created 2020/11/23 · arxiv updated 2021/01/04
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 non-local 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, a strange 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 \rm MS scheme at a scale of 2 GeV.