相关论文: Quark-gluon vertex in a momentum subtraction schem…
The quark-gluon vertex in Landau gauge is studied in the quenched approximation using the Sheikholeslami-Wohlert (SW) fermion action with mean-field improvement coefficients in the action and for the quark fields. We see that the form…
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 complete vertex is computed in two specific kinematical limits, while the Dirac-vector part is…
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…
We present the first results from a study of the quark--gluon vertex function in the Landau gauge. The results are obtained for quenched QCD with an O(a)-improved Wilson fermion action, at beta=6.0. We discuss plans for further study,…
We present results for the QCD running coupling obtained from measuring the quark-gluon vertex in Landau gauge with suitable renormalisation conditions. The issue of discretisation errors arising from the fermion action is discussed.
The complete tensor structure of the quark--gluon vertex in Landau gauge is determined at two kinematical points (`asymmetric' and `symmetric') from lattice QCD in the quenched approximation. The simulations are carried out at beta=6.0,…
We report on preliminary results for the triple-gluon and the quark-gluon vertex in Landau gauge. Our results are based on two-flavor and quenched lattice QCD calculations for different quark masses, lattice spacings and volumes. We discuss…
We present preliminary results on the computation of the QCD running coupling constant in the MOM_tilde scheme and Landau gauge with two flavours of dynamical Wilson quarks. Gluon momenta range up to about 7 GeV (beta=5.6, 5.8 and 6.0) with…
We present preliminary results on the computation of the QCD running coupling constant in the $\widetilde{MOM}$ scheme and Landau gauge with two flavours of dynamical Wilson quarks. Gluon momenta range up to about 7 GeV ($\beta =$ 5.6, 5.8…
The quark-gluon mixed condensate $g<\bar q \sigma_{\mu\nu} F_{\mu\nu} q>$ is calculated in the Gaussian approximation of the Field Correlator Method. In the large N_c limit and for zero mass quarks one obtains a simple result, $m^2_0 \equiv…
We compute the triple gluon, quark-gluon and ghost-gluon vertices of QCD at the symmetric subtraction point at two loops in the MSbar scheme. In addition we renormalize each of the three vertices in their respective momentum subtraction…
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…
We compute the QCD running coupling on the lattice as defined from the 3-gluon vertex. We present the results of an exploratory study at $\beta=6.0$ on a $16^4$ lattice, which show that for momenta larger than 2 \Gev, the coupling runs…
We show results for the quark-gluon vertex in the Landau gauge, using a mean-field improved Sheikholeslami-Wohlert fermion action. We compute all the three non-zero form factors of the vertex at zero gluon momentum, and compare them to the…
The Landau gauge four-gluon vertex is studied using high statistical lattice simulations for several momentum configurations. Furthermore, the outcome of the lattice QCD simulations is compared with calculations performed with continuum…
We determine the value of the quark condensate from quenched QCD simulations on the lattice in two ways: (i) by using the GMOR formula; (ii) by comparing the OPE prediction for the Goldstone pole contribution to the pseudoscalar vertex, at…
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…
A recent lattice calculation of the QCD running coupling is presented. The coupling is extracted from the force between two static quarks in the framework of the valence quark approximation. A value of the Lambda-parameter for zero quark…
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 compute the running QCD coupling on the lattice by evaluating two-point and three-point off-shell gluon Green's functions in a fixed gauge and imposing non-perturbative renormalisation conditions on them. Our exploratory study is…