Related papers: Reshuffling the OPE: Delocalized Operator Expansio…
A prescription for the short-distance expansion of Euclidean current correlators based on a delocalized modification of the multipole expansion of perturbative short-distance coefficient functions is proposed that appreciates the presence…
A generalization of Wilson's local OPE for the short-distance expansion of Euclidean current correlators, called delocalized operator expansion (DOE), which has been proposed recently, is discussed. The DOE has better convergence properties…
We review the status of the practical operator product expansion (OPE), when applied to two-point correlators of QCD currents which interpolate to mesonic resonances, in view of the violations of local quark-hadron duality. Covered topics…
Local quark-hadron duality violations in conventional applications of the operator product expansion are proposed to have their origin in the fact that the QCD vacuum or a hadronic state is not only characterized by nonvanishing expectation…
We discuss the current use of the operator product expansion in QCD calculations. Treating the OPE as an expansion in inverse powers of an energy-squared variable (with possible exponential terms added), approximating the vacuum expectation…
The role of the operator-product expansion in QCD calculations is discussed. Approximating the two-point correlation function by several terms and assuming an upper bound on the truncation error along the euclidean ray, we consider two…
Operator product expansions (OPEs) in quantum field theory (QFT) provide an asymptotic relation between products of local fields defined at points $x_1, \dots, x_n$ and local fields at point $y$ in the limit $x_1, \dots, x_n \to y$. They…
Since the operator product expansion (OPE) is applicable at short distance the OPE in QCD does not solve the long distance confinement problem involving hadron in QCD where the non-perturbative QCD is applicable. In this paper we show that…
We analytically calculate higher order corrections to coefficient functions of the operator product expansion (OPE) for the Euclidean correlator of two energy-momentum tensors in massless QCD. These are the three-loop contribution to the…
Because of the infrared renormalons, it is difficult to get power accuracy in the traditional approach to the Wilson's operator product expansion. Based on a new perturbative renormalization scheme for power-divergent operators, I propose a…
We examine the origin of possible failures of the quark-hadron local duality. In particular, we consider a correlator of two currents comprising heavy quark operators, and compare the evaluation by the Operator Product Expansion with the…
We apply a recently constructed model of analytic QCD in the Operator Product Expansion (OPE) analysis of the tau lepton decay data in the V+A channel. The model has the running coupling A(Q^2) with no unphysical singularities, i.e., it is…
A long-standing problem concerns the question how to consistently combine perturbative expansions in QCD with power corrections in the context of the operator product expansion (OPE), since the former exhibit ambiguities due to infrared…
In this paper analytical results are presented for higher order corrections to coefficient functions of the operator product expansion (OPE) for the correlator of two pseudoscalar gluonium operators \tilde{O}_1=G^{\mu \nu}\tilde{G}_{\mu…
The operator-product expansion(OPE) could be employed to obtain the lowest-order, nonlocal quark scalar condensate component of gluon vacuum polarization. In particular, nonlocal quark scalar condensate can be calculated by solving…
The contributions to the coefficient functions of the quark and the mixed quark-gluon condensate to mesonic correlators are calculated for the first time to all orders in the quark masses, and to lowest order in the strong coupling…
We study the operator product expansion of the plaquette (gluon condensate) and the self-energy of an infinitely heavy quark. We first compute their perturbative expansions to order $\alpha^{35}$ and $\alpha^{20}$, respectively, in the…
Motivated by the mixing of UV and IR effects, we test the OPE formula in noncommutative field theory. First we look at the renormalization of local composite operators, identifying some of their characteristic IR/UV singularities. Then we…
The Operator Product Expansion (OPE) of current correlators at short distances beyond perturbation theory in QCD, together with Cauchy's theorem in the complex energy plane, are the pillars of the method of QCD sum rules. This technique…
A method for calculating coefficient functions of the operator product expansion, which was previously derived for the non-singlet case, is generalized for the singlet coefficient functions. The resulting formula defines coefficient…