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

Open Access
Letter

Abstract.

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.

References

  1. 1.
    G. Colangelo, J. Gasser, H. Leutwyler, Nucl. Phys. B 603, 125 (2001) hep-ph/0103088CrossRefADSGoogle Scholar
  2. 2.
    J. Gasser, H. Leutwyler, Ann. Phys. 158, 142 (1984)CrossRefADSMathSciNetGoogle Scholar
  3. 3.
    J. Gasser, H. Leutwyler, Phys. Lett. B 125, 325 (1983)CrossRefADSGoogle Scholar
  4. 4.
    Particle Data Group Collaboration (K. Olive et al.), Chin. Phys. C 38, 090001 (2014)CrossRefGoogle Scholar
  5. 5.
    J. Bijnens, G. Ecker, Annu. Rev. Nucl. Part. Sci. 64, 149 (2014) arXiv:1405.6488 CrossRefADSGoogle Scholar
  6. 6.
    A. Jüttner, JHEP 01, 007 (2012) arXiv:1110.4859 CrossRefGoogle Scholar
  7. 7.
    V. Gülpers, G. von Hippel, H. Wittig, Phys. Rev. D 89, 094503 (2014) arXiv:1309.2104 CrossRefADSGoogle Scholar
  8. 8.
    S. Capitani, M. Della Morte, G. von Hippel, B. Knippschild, H. Wittig, PoS LATTICE2011, 145 (2011) arXiv:1110.6365 Google Scholar
  9. 9.
    P.A. Boyle, J.M. Flynn, A. Jüttner, C.T. Sachrajda, J.M. Zanotti, JHEP 05, 016 (2007) hep-lat/0703005Google Scholar
  10. 10.
    S. Güsken et al., Phys. Lett. B 227, 266 (1989)CrossRefADSGoogle Scholar
  11. 11.
    C. Alexandrou, F. Jegerlehner, S. Güsken, K. Schilling, R. Sommer, Phys. Lett. B 256, 60 (1991)CrossRefADSGoogle Scholar
  12. 12.
    UKQCD Collaboration (C. Allton et al.), Phys. Rev. D 47, 5128 (1993) hep-lat/9303009CrossRefGoogle Scholar
  13. 13.
    S. Aoki et al., Eur. Phys. J. C 74, 2890 (2014) arXiv:1310.8555 CrossRefADSGoogle Scholar

Copyright information

© The Author(s) 2015

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

Authors and Affiliations

  • Vera Gülpers
    • 1
  • 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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