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  • Letter
  • Open Access

Zemach and Friar radii of the proton and neutron from lattice QCD

Dalibor Djukanovic1,2, Georg von Hippel3, Harvey B. Meyer1,3, Konstantin Ottnad3, Miguel Salg3,*, and Hartmut Wittig1,3

  • *Contact author: msalg@uni-mainz.de
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Phys. Rev. D 110, L011503 – Published 17 July, 2024

DOI: https://doi.org/10.1103/PhysRevD.110.L011503

Abstract

We present the first lattice-QCD result for the Zemach and Friar radii of the proton and neutron. Our calculation includes both quark-connected and -disconnected diagrams and assesses all sources of systematic uncertainties arising from excited-state contributions, finite-volume effects, and the continuum extrapolation. At the physical point, we obtain for the proton rZp=(1.013±0.010(stat)±0.012(syst))  fm and rFp=(1.301±0.012(stat)±0.014(syst))  fm. These numbers suggest small values of the Zemach and Friar radii of the proton but are compatible with most of the experimental studies.

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Phys. Rev. D 110, L011503– Published 17 July, 2024
  • Received 5 October 2023
  • Revised 24 May 2024
  • Accepted 4 June 2024
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