Quark-gluon vertex from Nf=2 lattice QCD

Abstract

We study the quark-gluon vertex in the limit of vanishing gluon momentum using lattice QCD with 2 flavors of O(a) improved Wilson fermions, for several lattice spacings and quark masses. We find that all three form factors in this kinematics have a significant infrared strength, and that both the leading form factor ${\lambda }_1$, multiplying the tree-level vertex structure, and the scalar, chiral symmetry breaking form factor ${\lambda }_3$ are significantly enhanced in the infrared compared to the quenched (Nf=0) case. These enhancements are orders of magnitude larger than predicted by one-loop perturbation theory. We find only a weak dependence on the lattice spacing and quark mass.

arXiv comment24 pages, many figures. Minor changes, matches version published in Phys.Rev.D

References in corpus (54)

• Infrared Properties of QCD from Dyson-Schwinger equations
• Bethe-Salpeter Study of Vector Meson Masses and Decay Constants
• Pion mass and decay constant
• Pinch Technique: Theory and Applications
• The 2009 World Average of ${\alpha }_s$
• Chiral symmetry breaking in continuum QCD
• Imaging dynamical chiral symmetry breaking: pion wave function on the light front
• Sketching the Bethe-Salpeter kernel
• Non-perturbative quark, gluon and meson correlators of unquenched QCD
• Gauge bosons at zero and finite temperature
• The $\pi$, $K^{+}$, and $K^0$ electromagnetic form factors
• Pion electromagnetic form factor at spacelike momenta
• Light mesons in QCD and unquenching effects from the 3PI effective action
• Dressed-quark anomalous magnetic moments
• From Quarks and Gluons to Hadrons: Chiral Symmetry Breaking in Dynamical QCD
• Lattice Gluon and Ghost Propagators, and the Strong Coupling in Pure SU(3) Yang-Mills Theory: Finite Lattice Spacing and Volume Effects
• Nucleon isovector couplings from $N_f=2$ lattice QCD
• Nonperturbative structure of the quark-gluon vertex
• Scaling behavior of quark propagator in full QCD
• Nucleon mass and sigma term from lattice QCD with two light fermion flavors
• Natural constraints on the gluon-quark vertex
• ONE LOOP QED VERTEX IN ANY COVARIANT GAUGE: ITS COMPLETE ANALYTIC FORM
• Fully coupled functional equations for the quark sector of QCD
• Renormalisation and off-shell improvement in lattice perturbation theory
• The quark-gluon vertex in Landau gauge bound-state studies
• Dynamical chiral symmetry breaking and the fermion--gauge-boson vertex
• Quark-gluon vertex model and lattice-QCD data
• Building the Full Fermion-Photon Vertex of QED by Imposing Multiplicative Renormalizability of the Schwinger-Dyson Equations for the Fermion and Photon Propagators
• Gluon propagator and three-gluon vertex with dynamical quarks
• Nonperturbative improvement and tree-level correction of the quark propagator
• Quark-gluon vertex from lattice QCD
• A new method for determining the quark-gluon vertex
• Quark propagator in the Landau gauge
• Lattice evidence for the family of decoupling solutions of Landau gauge Yang-Mills theory
• Quark gap equation with non-abelian Ball-Chiu vertex
• Quark propagator with two flavors of O(a)-improved Wilson fermions
• Quark-gluon vertex in general kinematics
• Quark-gluon Vertex: A Perturbation Theory Primer and Beyond
• Unquenching effects in the quark and gluon propagator
• The moment $⟨x{⟩}_{u-d}$ of the nucleon from $N_f=2$ lattice QCD down to nearly physical quark masses
• Non-Abelian Ball-Chiu vertex for arbitrary Euclidean momenta
• Deep Inelastic Scattering in Improved Lattice QCD. I. The first moment of structure functions
• Transverse Ward-Takahashi Identity, Anomaly and Schwinger-Dyson Equation
• Quark-gluon vertex from the Landau gauge Curci-Ferrari model
• Exploring the Quark-Gluon Vertex with Slavnov-Taylor Identities and Lattice Simulations
• Infrared exponents and the strong-coupling limit in lattice Landau gauge
• Interplay of dynamical and explicit chiral symmetry breaking effects on a quark
• Checking the transverse Ward-Takahashi relation at one loop order in 4-dimensions
• The soft-gluon limit and the infrared enhancement of the quark-gluon vertex
• Transverse Symmetry Transformations and the Quark-Gluon Vertex Function in QCD
• Lattice Landau gauge quark propagator and the quark-gluon vertex
• Effect of the Quark-Gluon Vertex on Dynamical Chiral Symmetry Breaking
• Strongly-Coupled Unquenched QED4 Propagators Using Schwinger-Dyson Equations
• Gluon and Ghost Dynamics from Lattice QCD

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