Generalized Parton Distribution of Nucleon at Physical Pion Mass from Lattice QCD

ORAL

Abstract

The generalized parton distributions (GPDs) offer a window on three-dimensional imaging of the nucleon, providing understanding of how the fundamental properties of the nucleon, such as its mass and spin, arise from the underlying quark and gluon degrees of freedom. In this work, we present the first lattice calculation of the nucleon unpolarized and polarized GPDs at physical pion mass, using an $a \approx 0.09$~fm lattice ensemble with 2+1+1 flavors of highly improved staggered quarks (HISQ) generated by MILC Collaboration. We perform the GPD calculation in Breit frame using averaged nucleon boost momentum $P_z \approx 2.2$~GeV with nonzero momentum transfers in $[0.2,1.0]\text{ GeV}^2$. The three-dimensional distribution of the nucleon as functions of $x$ and $Q^2$ is presented, along with the three-dimensional nucleon tomography and impact-parameter--dependent distribution.

*We thank the MILC Collaboration for sharing the lattices used to perform this study. The LQCD calculations were performed using the Chroma software suite. This research used resources of the National Energy Research Scientific Computing Center, 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 through ERCAP; facilities of the USQCD Collaboration, which are funded by the Office of Science of the U.S. Department of Energy, and supported in part by Michigan State University through computational resources provided by the Institute for Cyber-Enabled Research (iCER). The work of HL is partially supported by the US National Science Foundation under grant PHY 1653405 ``CAREER: Constraining Parton Distribution Functions for New-Physics Searches'' and by the Research Corporation for Science Advancement through the Cottrell Scholar Award ``Unveiling the Three-Dimensi

–

Presenters

  • Huey-Wen Lin

    • Michigan State University

Authors

  • Huey-Wen Lin

    • Michigan State University