Infrared-suppressed QCD coupling and the hadronic contribution to muon g-2

TL;DR

This paper explores a modified QCD model with suppressed infrared coupling, deriving a Landau-singularity-free coupling that accurately predicts the hadronic contribution to muon g-2 by matching experimental data and theoretical constraints.

Contribution

It introduces a QCD variant with IR-suppressed coupling consistent with lattice results and high-energy QCD, and demonstrates its effectiveness in calculating muon g-2 contributions.

Findings

The IR-suppressed coupling is free of Landau singularities.

The model reproduces the hadronic vacuum polarization contribution to muon g-2.

Consistent condensate values are extracted from tau decay data.

Abstract

A variant of QCD with the coupling suppressed in the infrared (IR) regime, as suggested by large-volume lattice calculations of the Landau-gauge gluon and ghost dressing functions, is considered. The coupling is further restricted by the condition of approximate coincidence with perturbative QCD in the high momentum regime, and by the $\tau$-lepton semihadronic decay rate in the intermediate momentum regime, the rate which is evaluated by a renormalon-motivated resummation method. The obtained coupling turns out to be free of Landau singularities. The $D=4,6$ condensate values of the Adler function are then extracted by application of the Borel sum rules to the OPAL and ALEPH (V+A)-channel data of $\tau$-decay, and the corresponding V-channel condensate values are deduced as well. We then show that the correct value of the hadronic vacuum polarization contribution to the muon anomalous magnetic moment, $a_{\mu}^{\rm had(1)}$, is reproduced by regularizing the $D=4,6$ OPE terms in the V-channel Adler function with IR-regularization masses ${\cal M}_{D/2} \lesssim 1 \ {\rm GeV}$, suggesting the internal consistency of the presented QCD framework.