Unquenching the Quark-Antiquark Green's Function

Abstract

We propose a nonperturbative resummation scheme for the four-point connected quark-antiquark Green's function $G^4$ that shows how the Bethe-Salpeter equation may be `unquenched' with respect to quark-antiquark loops. This mechanism allows to dynamically account for hadronic meson decays and multiquark structures whilst respecting the underlying symmetries. An initial approximation to the four-point Schwinger-Dyson equation -- suitable for phenomenological application -- is examined numerically in a couple of aspects. It is demonstrated that this approximation explicitly maintains the correct asymptotic limits and contains the physical resonance structures in the near timelike region in the quark-antiquark channel whereas no resonances are found in the diquark channel, respectively.

21 pages, 13 figures

References in corpus (1)

• The lightest scalar nonet

Cited by in corpus (16)

• Infrared Properties of QCD from Dyson-Schwinger equations
• Baryons as relativistic three-quark bound states
• Survey of J=0,1 mesons in a Bethe-Salpeter approach
• The quark-gluon vertex in Landau gauge bound-state studies
• On the Quark-Gluon Vertex and Quark-Ghost Kernel: combining Lattice Simulations with Dyson-Schwinger equations
• Pion cloud effects on baryon masses
• A covariant view on the nucleons' quark core
• Matrix algorithms for solving (in)homogeneous bound state equations
• Octet and Decuplet masses: a covariant three-body Faddeev calculation
• Vector mesons as dynamical resonances in the Bethe-Salpeter framework
• Effects of a dressed quark-gluon vertex in pseudoscalar heavy-light mesons
• The $\sigma$-meson: four-quark vs. two-quark components and decay width in a Bethe-Salpeter approach
• Bethe-Salpeter studies of mesons beyond rainbow-ladder
• On the low-energy spectrum of an SU(2) gauge theory with dynamical fermions
• Quark sector of Coulomb gauge Quantum Chromodynamics
• Recent Developments in the Bethe-Salpeter Description of Light Mesons