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x-dependent proton GPDs in lattice QCD

ORAL

Abstract

We present a novel calculation of the proton chiral-even unpolarized and helicity quark generalized parton distributions (GPDs), as extracted from numerical simulations of lattice QCD. We use the quasi-distribution method, which relies on matrix elements of fast-moving hadrons, and non-local operators. This method was developed for parton distribution functions (PDFs) and was recently extended for the study of GPDs. We obtain results for nucleon momentum up to 1.67 GeV, and momentum-transfer squared up to 1 GeV$^2$. The calculation is performed on one ensemble of two degenerate light, a strange and a charm quark ($N_f=2+1+1$) of maximally twisted mass fermions with a clover term, reproducing a pion mass of 260 MeV. The renormalized quasi-GPDs are given in the $\overline{\rm MS}$ scheme, evolved at a scale of 2 GeV, and are matched to light-cone GPDs using one-loop perturbation theory within Large Momentum Effective Theory.

Authors

  • Martha Constantinou

    Temple University, Temple

  • Constantia Alexandrou

    University of Cyprus

  • Krzysztof Cichy

    Adam Mickiewicz University

  • Kyriacos Hadjiyiannakou

    University of Cyprus, University of Cyprus, The Cyprus Institute

  • Karl Jansen

    NIC, DESY

  • Aurora Scapellato

    Adam Mickiewicz University

  • Fernanda Steffens

    Institute for Strahlen and Kernphysik, Rheinische, Friedrich-Wilhelms-University at Bonn