Related papers: Power corrections and Landau singularity
We argue that the appearance of the Landau pole in the running coupling of QCD introduces 1/Q^2 power corrections in current correlation functions. These terms are not accounted for by the standard operator product expansion and is the…
We overview the issue of the power corrections to the parton model, mostly within the context of QCD sum rules. There are a few sources of the power corrections responsible for various qualitative effects. The basic idea that the power…
The infrared features of Landau gauge QCD are studied by the lattice simulation of $\beta=6.0, 16^4, 24^4, 32^4$ and $\beta=6.4, 32^4, 48^4$. We adopt two definitions of the gauge field; 1) $U-$linear 2) $\log U$ and measured the gluon…
Some features of the solutions to the truncated Dyson-Schwinger equations(DSEs) for the propagators of QCD in Landau gauge are summarized. In particular, the Kugo-Ojima confinement criterion is realized, and positivity of transverse gluons…
Approximate solutions for the gluon and ghost propagators as well as the running coupling in Landau gauge Yang-Mills theories are presented. These propagators obtained from the corresponding Dyson-Schwinger equations are in remarkable…
Recent progress in the solution of Schwinger-Dyson equations (SDE), as well as lattice simulation of pure glue QCD, indicate that the gluon propagator and coupling constant are infrared (IR) finite. We discuss how this non-perturbative…
The connection between renormalons and power corrections is investigated for the typical infrared renormalon integral assuming the effective coupling constant has an infrared fixed point of an entirely perturbative origin. It is shown the…
Nonperturbative studies of the strong running coupling constant in the infrared region are discussed. Starting from the analyses of the Dyson -- Schwinger equations in the gauge sector of QCD, the conclusion is made on an incomplete fixing…
We investigate the power-suppressed corrections to the mean values of various quantities that characterise the shapes of final states in deep inelastic lepton scattering. Our method is based on an analysis of one-loop Feynman graphs…
We investigate the infrared behaviour of gluon and ghost propagators in Landau gauge QCD by means of an exact renormalisation group equation. We explain how, in general, the infrared momentum structure of Green functions can be extracted…
The infrared behaviour of the gluon and ghost propagators in Landau gauge QCD is reviewed. The Kugo-Ojima confinement criterion and the Gribov-Zwanziger horizon condition result from quite general properties of the ghost Dyson-Schwinger…
Even for short-distance dominated observables the QCD perturbation expansion is never complete. The divergence of the expansion through infrared renormalons provides formal evidence of this fact. In this article we review how this apparent…
The dispersive approach to QCD is applied to the study of the inclusive tau lepton hadronic decay. This approach provides the unified integral representations for the hadronic vacuum polarization function, related R function, and Adler…
We estimate the effects of non-perturbative physics on the differential distributions of infrared- and collinear-safe $e^+e^-$ event shape variables, by extending the notion of an infrared-regular effective strong coupling, which accounts…
We argue that accounting for higher order corrections in QCD by integrating a running coupling constant through an infrared region can be most easily done with making use of a scheme without the Landau pole. Within this approach the entire…
Power corrections to hadronic event shapes are estimated using a recently suggested relationship between perturbative and non-perturbative effects in QCD. The infrared cutoff dependence of perturbative calculations is related to…
Infrared power corrections for Minkowskian QCD observables are analyzed in the framework of renormalon resummation, motivated by analogy with the skeleton expansion in QED and the BLM approach. Performing the ``massive gluon'' renormalon…
We present a specific class of models for an infrared-finite analytic QCD coupling, such that at large space-like energy scales the coupling differs from the perturbative one by less than any inverse power of the energy scale. This…
We show that the O(Lambda) ambiguity in the pole mass can be fixed in a natural way by introducing a modified nonperturbative V-scheme momentum space coupling tilde-alphaV(q) where the confining contributions have been subtracted out. The…
We analyze the pertubative contributions to the $D^4 R^4$ and $D^6 R^4$ couplings in the low-energy effective action of type II string theory compactified on a torus $T^d$, with particular emphasis on two-loop corrections. In general, it is…