Related papers: Four Gluon Vertex from Lattice QCD
Nonperturbative properties of gluons are studied in SU(3) lattice QCD at the quenched level. The first subject is a functional-form analysis of the gluon propagator $D_{\mu\nu}^{ab}(x)$ in the Landau gauge. We find that the gluon propagator…
We study the nonperturbative structure of the quark-photon vertex in Landau gauge. To this end, we utilize lattice QCD data for the vector current for two mass-degenerate quark flavours and extract all longitudinal and transverse form…
The running coupling constant can be estimated by computing gluon two- and three-point Green functions from the lattice. Computing in lattice implies working in a fixed gauge sector (Landau). An source of systematic uncertainty is then the…
We summarise results on the infrared behaviour of Landau gauge QCD from the Green's functions approach and lattice calculations. Approximate, nonperturbative solutions for the ghost, gluon and quark propagators as well as first results for…
A crucial step in extracting physical predictions from lattice QCD simulations is the scale setting, i.e. the determination of the lattice spacing ($a$) in physical units. Herein, the relative scale setting for different $\beta$'s is…
A future Electron-Ion Collider will enable the gluon contributions to the gravitational form factors of the proton to be constrained experimentally for the first time. Here, the first calculation of these form factors from lattice Quantum…
In the present work we discuss certain characteristic features encoded in some of the fundamental QCD Green's functions, whose origin can be traced back to the nonperturbative masslessness of the ghost field, in the Landau gauge.…
The standard Feynman rules used for perturbative calculations in quantum chromodynamics (QCD) are derived from a Lagrangian that is first-order in derivatives. It includes a three-point quark-gluon vertex which obscures the precise…
This PhD dissertation is devoted to a non-perturbative study of QCD correlators. The main tool that we use is lattice QCD. We concentrated our efforts on the study of the main correlators of the pure Yang - Mills theory in the Landau gauge,…
There has been growing evidence that the infrared enhancement of the form factors defining the full quark-gluon vertex plays an important role in realizing a dynamical breakdown of chiral symmetry in quantum chromodynamics, leading to the…
We present a practical method for the solution of the quark-gluon vertex for use in Bethe--Salpeter and Dyson--Schwinger calculations. The efficient decomposition into the necessary covariants is detailed, with the numerical algorithm…
The infrared behaviour of QCD Green's functions in Landau gauge has been focus of intense study. Different non-perturbative approaches lead to a prediction in line with the conditions for confinement in local quantum field theory as spelled…
We compute the quark-gluon vertex in quenched lattice QCD, in the Landau gauge using an off-shell mean-field O(a)-improved fermion action. The Dirac-vector part of the vertex is computed for arbitrary kinematics. We find a substantial…
Polygonal lines are used for the paths of the gluon field phase factors entering in the definition of gauge invariant quark Green's functions. This allows classification of the Green's functions according to the number of segments the…
In this talk we present a new method for determining the nonperturbative quark-gluon vertex, which constitutes a crucial ingredient for a variety of theoretical and phenomenological studies. This new method relies heavily on the exact…
We present new results for the transversely projected three-gluon vertex from quenched lattice QCD simulations using standard Wilson action. While previous works focused in some particular kinematics such as the symmetric $(q^2 = r^2 =…
We study the UV-scaling of the flavorless gluon propagator in the Landau gauge in an energy window up to 9 GeV. Dominant hypercubic lattice artifacts are eliminated. A large set of renormalization schemes is used to test asymptotic scaling.…
Lattice-based investigations of two fundamental QCD quantities are described, namely the gluon and quark propagators in Landau gauge. We have studied the Landau gauge gluon propagator using a variety of lattices with spacings from a = 0.17…
A model for the dressed quark-gluon vertex, at zero gluon momentum, is formed from a nonperturbative extension of the two Feynman diagrams that contribute at 1-loop in perturbation theory. The required input is an existing ladder-rainbow…
We study gluon propagator in Landau gauge with lattice QCD, where we use an improved lattice action. The calculation of gluon propagator is performed on lattices with the lattice spacing from 0.40 fm to 0.24 fm and with the lattice volume…