相关论文: QCD Renormalons and Higher Twist Effects
We propose an extraction of the running coupling constant of QCD in the infrared region from experimental data on deep inelastic inclusive scattering at Bjorken x -> 1. We first attempt a perturbative fit of the data that extends NLO PQCD…
We give a summary of existing results on higher twist distribution amplitudes of vector mesons in QCD. Special attention is payed to meson mass corrections which turn out to be large. A ``shopping list'' is presented of most important…
We calculate the contribution of the higher twist Feynman diagrams to the large-$p_T$ inclusive pion production cross section in proton-proton collisions in the case of the running and frozen coupling approaches within holographic QCD. The…
This is a doctoral thesis dissertation developed in the frame of theoretical QCD predictions, with focus on two main topics. On the one hand, the large-order bahavior of perturbative QCD series is discussed. By reviewing the main…
Renormalization scheme uncertainties in the next-next-to-leading order QCD predictions are discussed. To obtain an estimate of these uncertainties it is proposed to compare predictions in all schemes that do not have unnaturally large…
The summary of the results of our next-to-next-to-leading fits of Tevatron experimental data for $xF_3$ structure function of the $\nu N$ deep-inelastic scattering is given. The special attention is paid to the extraction of twist-4…
After reviewing basic facts about large-order behaviour of perturbation expansions in various fields of physics, I consider several alternatives to the Borel summation method and discuss their relevance to different physical situations.…
Infrared safe differential cross sections, such as event shape distributions, can be measured over wide kinematic ranges, from regions where fixed order calculations are adequate to regions where nonperturbative dynamics dominate. Such…
Recently, it has been shown that the concept of the pole mass of a heavy quark becomes ambiguous beyond perturbation theory, because of the presence of infrared renormalons. We argue that the predictions of heavy quark effective theory,…
Infrared renormalons in Quantum Chromodynamics are associated with non-perturbative corrections to short distance observables. Linear renormalons, i.e. such that the associated non-perturbative corrections scale like one inverse power of…
It is demonstrated that the infrared renormalon calculus indicates that the QCD theoretical expressions for the Gross-Llewelln Smith sum rules and for the Bjorken polarized and unpolarized ones contain an identical negative twist-4 1/Q^2…
Exact large-$N_{f}$ results for the QCD Adler $D$-function and Deep Inelastic Scattering sum rules are used to resum to all orders the portion of QCD perturbative coefficients containing the highest power of…
In this thesis, we have investigated the higher twist structure functions in the recently developed method based on light-front Hamiltonian QCD. Because of various special properties of light-front QCD, this is a more intuitive approach…
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…
Infrared and collinear events shapes are suited to directly probe properties of hard QCD. They are traditionally used to measure the strong coupling and to test the gauge structure of QCD. Perturbative predictions exist in several…
We present a systematic study of twist-3 and twist-4 light-cone distribution amplitudes of the K meson in QCD. The structure of SU(3)-breaking corrections is studied in detail. Non-perturbative input parameters are estimated from QCD sum…
A method of evaluation of spacelike QCD observables ${\cal D}(Q^2)$ is presented, motivated by the renormalon structure of these quantities.
The theoretical status of perturbative QED and QCD corrections to deep inelastic scattering is reviewed.
This talk discusses the power behaved corrections to fragmentation functions for the current jet in non-singlet deep inelastic scattering. These corrections are estimated by means of a renormalon model using a dispersive approach. The…
Perturbative calculations of the static QCD potential have the $u=3/2$ renormalon uncertainty. In the multipole expansion performed within pNRQCD, this uncertainty at LO is known to get canceled against the ultrasoft correction at NLO. To…