• Open Access

Determination of the QCD Λ Parameter and the Accuracy of Perturbation Theory at High Energies

Mattia Dalla Brida, Patrick Fritzsch, Tomasz Korzec, Alberto Ramos, Stefan Sint, and Rainer Sommer (ALPHA Collaboration)
Phys. Rev. Lett. 117, 182001 – Published 24 October 2016
PDFHTMLExport Citation

Abstract

We discuss the determination of the strong coupling αMS¯(mZ) or, equivalently, the QCD Λ parameter. Its determination requires the use of perturbation theory in αs(μ) in some scheme s and at some energy scale μ. The higher the scale μ, the more accurate perturbation theory becomes, owing to asymptotic freedom. As one step in our computation of the Λ parameter in three-flavor QCD, we perform lattice computations in a scheme that allows us to nonperturbatively reach very high energies, corresponding to αs=0.1 and below. We find that (continuum) perturbation theory is very accurate there, yielding a 3% error in the Λ parameter, while data around αs0.2 are clearly insufficient to quote such a precision. It is important to realize that these findings are expected to be generic, as our scheme has advantageous properties regarding the applicability of perturbation theory.

  • Figure
  • Figure
  • Figure
  • Received 22 April 2016

DOI:https://doi.org/10.1103/PhysRevLett.117.182001

Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.

Published by the American Physical Society

Physics Subject Headings (PhySH)

Particles & Fields

Authors & Affiliations

Mattia Dalla Brida1, Patrick Fritzsch2, Tomasz Korzec3, Alberto Ramos4, Stefan Sint5, and Rainer Sommer1,6 (ALPHA Collaboration)

  • 1John von Neumann Institute for Computing (NIC), DESY, Platanenallee 6, 15738 Zeuthen, Germany
  • 2Instituto de Física Teórica UAM/CSIC, Universidad Autónoma de Madrid, C/ Nicolás Cabrera 13–15, Cantoblanco, Madrid 28049, Spain
  • 3Department of Physics, Bergische Universität Wuppertal, Gaußstrasse 20, 42119 Wuppertal, Germany
  • 4Theoretical Physics Department, CERN, CH 1211 Geneva 23, Switzerland
  • 5School of Mathematics, Trinity College Dublin, Dublin 2, Ireland
  • 6Institut für Physik, Humboldt-Universität zu Berlin, Newtonstrasse 15, 12489 Berlin, Germany

Article Text

Click to Expand

Supplemental Material

Click to Expand

References

Click to Expand
Issue

Vol. 117, Iss. 18 — 28 October 2016

Reuse & Permissions
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review Letters

Reuse & Permissions

It is not necessary to obtain permission to reuse this article or its components as it is available under the terms of the Creative Commons Attribution 3.0 License. This license permits unrestricted use, distribution, and reproduction in any medium, provided attribution to the author(s) and the published article's title, journal citation, and DOI are maintained. Please note that some figures may have been included with permission from other third parties. It is your responsibility to obtain the proper permission from the rights holder directly for these figures.

×

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×