Pseudoscalar qqbar mesons and effective QCD coupling enhanced by <A^2> condensate

Abstract

Recent developments provided evidence that the dimension 2 gluon condensate <A^2> is important for the nonperturbative regime of Yang-Mills theories (quantized in the Landau gauge). We show that it may be relevant for the Dyson-Schwinger approach to QCD. In order that this approach leads to a successful hadronic phenomenology, an enhancement of the effective quark-gluon interaction seems to be needed at intermediate (p^2 \sim 0.5 GeV^2) momenta. It is shown that the gluon condensate <A^2> provides such an enhancement. It is also shown that the resulting effective strong running coupling leads to the sufficiently strong dynamical chiral symmetry breaking and successful phenomenology at least in the light sector of pseudoscalar mesons.

revtex4, 4 eps figures, 8 pages, improved presentation, to appear in Phys. Rev. D

References in corpus (3)

• Propagators and running coupling from SU(2) lattice gauge theory
• Modified instanton profile effects from lattice Green functions
• Infrared Exponents and the Running Coupling of Landau gauge QCD and their Relation to Confinement

Cited by in corpus (7)

• Two loop effective potential for < A^2_μ> in the Landau gauge in quantum chromodynamics
• Quantum properties of a non-Abelian gauge invariant action with a mass parameter
• eta and eta' mesons and dimension 2 gluon condensate <A^2>
• $\eta$ and ${\eta }^{\prime }$ mesons in the Dyson-Schwinger approach using a generalization of the Witten-Veneziano relation
• A Dyson-Schwinger model beyond isospin limit prepared for investigating U_A(1)-breaking temperature dependence
• Pion observables calculated in Minkowski and Euclidean spaces with Ansätze for quark propagators
• Aspects of model dependence of eta'-eta complex treated by going beyond the isospin limit