The Euclidean Adler function and its interplay with ΔαQEDhad \Delta {\alpha}_{\textrm{QED}}^{\textrm{had}} and αs_{s}

Feb 2, 2023
55 pages
Published in:
  • JHEP 04 (2023) 067
  • Published: Apr 17, 2023
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Abstract: (Springer)
Three different approaches to precisely describe the Adler function in the Euclidean regime at around 2 GeVs are available: dispersion relations based on the hadronic production data in e+^{+}e^{−} annihilation, lattice simulations and perturbative QCD (pQCD). We make a comprehensive study of the perturbative approach, supplemented with the leading power corrections in the operator product expansion. All known contributions are included, with a careful assessment of uncertainties. The pQCD predictions are compared with the Adler functions extracted from ΔαQEDhad \Delta {\alpha}_{\textrm{QED}}^{\textrm{had}} (Q2^{2}), using both the DHMZ compilation of e+^{+}e^{−} data and published lattice results. Taking as input the FLAG value of αs_{s}, the pQCD Adler function turns out to be in good agreement with the lattice data, while the dispersive results lie systematically below them. Finally, we explore the sensitivity to αs_{s} of the direct comparison between the data-driven, lattice and QCD Euclidean Adler functions. The precision with which the renormalisation group equation can be tested is also evaluated.
Note:
  • 56 pages, 22 figures, 14 tables. Published version
  • Correlation Functions
  • Effective Field Theories of QCD
  • The Strong Coupling
  • quantum chromodynamics: perturbation theory
  • quantum chromodynamics: Euclidean
  • lattice
  • quantum electrodynamics
  • dispersion
  • operator product expansion
  • GeV