The scalar radius of the pion from lattice QCD in the continuum limit

  • Vera GülpersEmail author
  • Georg von Hippel
  • Hartmut Wittig
Open Access


We extend our study (Phys. Rev. D 89, 094503 (2014)) of the pion scalar radius in two-flavour lattice QCD to include two additional lattice spacings as well as lighter pion masses, enabling us to perform a combined chiral and continuum extrapolation. We find discretisation artefacts to be small for the radius, and confirm the importance of the disconnected diagrams in reproducing the correct chiral behaviour. Our final result for the scalar radius of the pion at the physical point is \( \langle r^{2}\rangle^{\pi}_{s}=0.600\pm 0.052\) fm2, corresponding to a value of \( \overline{\ell}_{4}=4.54\pm 0.30\) for the low-energy constant \( \overline{\ell}_{4}\) of NLO chiral perturbation theory.


Form Factor Lattice Spacing Pion Mass Scalar Form Factor Continuum Extrapolation 
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© The Author(s) 2015

Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Authors and Affiliations

  • Vera Gülpers
    • 1
    Email author
  • Georg von Hippel
    • 1
  • Hartmut Wittig
    • 1
    • 2
  1. 1.PRISMA Cluster of Excellence and Institut für KernphysikJohannes Gutenberg-Universität MainzMainzGermany
  2. 2.Helmholtz Institute MainzJohannes Gutenberg-Universität MainzMainzGermany

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