Related papers: Landau gauge condensates from global color model
We compute the dimension-2 condensate, <A^2>, and the dimension-4 mixed condensate, <\bar q A q>, from the recent quenched lattice results for the quark propagator in the Landau gauge. We fit the lattice data to the Operator Product…
Based on the quark propagator in the instanton dilute liquid approximation, we calculate analytically the quark condensate $<\bar{q}q>$, the mixed quark gluon condensate $g_{s}<\bar{q}G_{\mu\nu}\sigma^{\mu\nu}q>$ and the four quark…
We give a short overview of our work concerning the dimension two operator A^2 in the Landau gauge and its generalizations to other gauges. We conclude by discussing recent work that leads to a renormalizable gauge invariant action…
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…
Lattice simulations along with studies in continuum QCD indicate that non-perturbative quantum fluctuations lead to an infrared regularisation of the gluon propagator in covariant gauges in the form of an effective mass-like behaviour. In…
We test gauge/string duality by evaluating expectation values of small Wilson loops in pure Yang-Mills theories. On the gauge-theory side, there exists rich phenomenology. The dual formulation provides with a universal language to evaluate…
We determine the non-perturbative gluon condensate of four-dimensional SU(3) gauge theory in a model independent way. This is achieved by carefully subtracting high order perturbation theory results from non-perturbative lattice QCD…
We present an analytic description of numerical results for the Landau-gauge SU(2) gluon propagator D(p^2), obtained from lattice simulations (in the scaling region) for the largest lattice sizes to date, in d = 2, 3 and 4 space-time…
The gluon and quark condensates and their temperature dependence are investigated within QCD premises. The input for the former is a gauge invariant $gg$ kernel made up of the direct (D), exchange (X) and contact(C) QCD interactions in the…
Gluon two- and three-point Green Functions computed in Landau gauge from the lattice show the existence of power corrections to the purely perturbative expressions, that can be explained through an Operator Product Expansion as the…
We construct the multiplicatively renormalizable effective potential for the mass dimension two local composite operator A^2 in linear covariant gauges. We show that the formation of <A^2> is energetically favoured and that the gluons…
The bounds on the values of gluon, four-quark and quark-gluon condensates are derived from the requirement of consistency of the sum rules for various correlators of the hybrid current $a_{\mu}=g\bar d\gamma_{\rho}\tilde G_{\rho\mu}u$. The…
The mixed quark-gluon condensate is another chiral order parameter in QCD, which plays an important role in the application of QCD sum rules. In this letter, we study the properties of quark-gluon mixed condensate at finite temperature and…
Gluon propagator in the infrared limit, computed in the Landau gauge, can be cast into an universal form with a running mass for the gluon. In this way we are able to show that all the proposals appeared so far in literature are equivalent…
We discuss the 2PPI expansion, a summation of the bubble graphs up to all orders, by means of the 2D Gross-Neveu toy model, whose exact mass gap and vacuum energy are known. Then we use the expansion to give analytical evidence that a…
The world-line formalism is used for the evaluation of the mixed heavy-quark-gluon condensate in two models of QCD - the stochastic vacuum model and the dual superconductor one. Calculations are performed for an arbitrary dimensionality of…
In this article we derive the integral equation that controls the momentum dependence of the effective gluon mass in the Landau gauge. This is accomplished by means of a well-defined separation of the corresponding "one-loop dressed"…
The gluon propagator in Landau gauge is calculated in quenched QCD on a large (32^3X64) lattice at beta=6.0. In order to assess finite volume and finite lattice spacing artefacts, we also calculate the propagator on a smaller volume for two…
We consider various special cases of gluon condensates at finite temperature. The gluon condensate for an ideal gas of gluons with a given vacuum expectation value is introduced for the sake of comparison with that calculated using the…
We present data for the gluon and quark propagators computed in the standard lattice Landau's gauge and for three values of the covariant gauge-fixing parameter lambda=0,8,16. Our results are obtained using the SU(3) Wilson action in the…