We trace here instantons through the analysis of pure Yang-Mills gluon Green functions in the Landau gauge for a window of IR momenta (0.4
We present a study of αMOM(p) at small p computed from the lattice in the quenched approximation (nf = 0). It shows a dramatic ∝ p4 law which can be understood within an instanton liquid model. In this framework the prefactor gives a direct measure of the instanton density in thermalised configurations. A preliminary result for this density is...
We give a more transparent understanding of the vacuum expectation value of the renormalized local operator A2 by relating it to the gluon propagator integrated over the momentum. The quadratically divergent perturbative contribution is subtracted and the remainder, dominantly due to the O(1/p2) correction to the perturbative propagator at...
The next-to-leading-order (NLO) term in the operator product expansion (OPE) of the quark propagator vector part Zψ and the vertex function g1 of the vector current in the Landau gauge should be dominated by the same ⟨A2⟩ condensate as in the gluon propagator. On the other hand, the perturbative part has been calculated to a very high precision...