Related papers: On power corrections to event shapes
We calculate and resum a perturbative expansion of nuclear enhanced power corrections to the structure functions measured in deeply inelastic scattering of leptons on a nuclear target. Our results for the Bjorken $x$-, $Q^2$- and…
The normalization of the gluon condensate and of renormalon-related power corrections in QCD is computed under the assumption that their ``perturbative'' part dominates over any eventual extra contribution from the non-trivial vacuum. 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…
We estimate the non-perturbative power-suppressed corrections to heavy flavour fragmentation and correlation functions in e^+e^- annihilation, using a model based on the analysis of one-loop Feynman graphs containing a massive gluon. This…
We review status of the power corrections in QCD. The topics include shape variables, unconventional 1/Q^2 corrections, tachyonic gluon mass as a fit parameter to the 1/Q^2 corrections. The selection of the material is determined mostly by…
We discuss power corrections to infrared safe cross sections and event shapes, and identify a nonperturbative function that governs 1/Q corrections to these quantities.
High-order behavior of the perturbative expansion for short-distance observables in QCD is intimately related to the contributions of small momenta in the corresponding Feynman diagrams and this correspondence provides one with a useful…
I present a unifying scheme for hadronic functions that comprises logarithmic corrections due to gluon emission in perturbative QCD, as well as power-behaved corrections of nonperturbative origin. The latter are derived by demanding that…
We present a new semi-numerical method to compute leading hadronisation corrections to two-jet event shapes in $e^+e^-$ annihilation. The formalism we present utilises the dispersive approach, where the magnitude of power corrections is…
We report on several methodologically different NNLO determinations of the strong coupling constant from event shapes and related observables in e+e- annihilation. The event shape distributions are analyzed within a combined framework of…
We elaborate on the relation between perturbative and power-like corrections to short-distance sensitive QCD observables. We confront theoretical expectations with explicit perturbative calculations existing in literature. As is expected,…
Perturbative expansions for short-distance quantities in QCD are factorially divergent and this deficiency can be turned into a useful tool to investigate nonperturbative corrections. In this work, we use this approach to study the…
We present the most accurate calculation for the pion and kaon electromagnetic form factors in the framework of perturbative QCD, where the power corrections up to twist-4 of the meson distribution amplitudes and the next-to-leading-order…
We compute power corrections to mean values of hadronic event shapes - the thrust and the C parameter - of tagged b quark events in electron positron annihilation, using the dispersive approach. We find that the leading power corrections…
We compute the next-to-next-to-leading order (NNLO) QCD corrections to the six most important event shape variables related to three-particle final states in electron-positron annihilation. The corrections are sizeable for all variables,…
We review the physics of the power corrections to the parton model. In the first part, we consider the power corrections which characterize the infrared sensitivity of Feynman graphs when the contribution of short distances dominates. The…
Applying the dispersion approach we compute perturbative QCD corrections to the power suppressed soft contribution of $B \to \gamma \ell \nu$ at leading twist. QCD factorization for the $B \to \gamma^{\ast}$ form factors is demonstrated…
The analytical perturbative approach, if taken to the limit of its applicability, allows one to predict an energy independent limit for the one-particle invariant density in QCD jets E dn/d^3p at very small momenta p. This is a direct…
It is widely believed that hadronisation leads to 1/Q corrections to e+e- event shapes. We show that there are further corrections, proportional to (ln Q)^A/Q with A=4C_A/beta_0~=1.6, associated with hadron masses and whose relative…
The duality between QCD perturbative series and power corrections recently conjectured by Narison and Zakharov is analyzed. We propose to study correlations between both contributions as diagnostics tool. A very strong correlation between…