Bound state approach to the QCD coupling at low energy scales

Abstract

We exploit theoretical results on the meson spectrum within the framework of a Bethe-Salpeter (BS) formalism adjusted for QCD, in order to extract an ``experimental'' coupling α_s^{exp}(Q^2) below 1 GeV by comparison with the data. Our results for α_s^{exp}(Q^2) exhibit a good agreement with the infrared safe Analytic Perturbation Theory (APT) coupling from 1 GeV down to 200 MeV. As a main result, we claim that the combined BS-APT theoretical scheme provides us with a rather satisfactory correlated understanding of very high and low energy phenomena.

Revised version, to appear on Physical Review Letters. 7 pages, 2 figures, Revtex

References in corpus (3)

• Decay constants of the heavy-light mesons from the field correlator method
• Practical techniques of analytic perturbation theory of QCD
• On the Fourier transformation of Renormalization Invariant Coupling

Cited by in corpus (2)

• QCD coupling below 1 GeV from quarkonium spectrum
• Adler function in the analytic approach to QCD