Related papers: Higher-twist contributions in exclusive processes
In this talk it is reported on an analysis of hard exclusive leptoproduction of pions within the handbag approach. It is argued that recent measurements of this process performed by HERMES and CLAS clearly indicate the occurrence of strong…
We have compared the existing experimental data on the leading power corrections to the structure functions $F_2(x,Q^2), F_3(x,Q^2)$, and $F_L(x,Q^2)$ with the IR-renormalon model predictions for higher-twist contributions. Our analysis…
The recent development of scintillation crystals combined with $\gamma$-rays sources opens the way to an imaging concept based on Compton scattering, namely Compton scattering tomography (CST). The associated inverse problem rises many…
We show how to fix the renormalization scale for hard-scattering exclusive processes such as deeply virtual meson electroproduction by applying the BLM prescription to the imaginary part of the scattering amplitude and employing a fixed-t…
We carry out the first complete calculation of kinematic power corrections $\sim t/Q^2$ and $\sim m^2/Q^2$ to several key observables in Deeply Virtual Compton Scattering. The issue of convention dependence of the leading twist…
We consider hard leptoproduction of a photon on a spin-one target and give the general azimuthal angular dependence of the differential cross section. Furthermore, we estimate the beam spin asymmetry for an unpolarized deuteron target at…
The calculation of higher twist (or dimension) corrections to physical quantities using operator product expansions is delicate. If dimensional regularization is used to regulate the ultra-violet divergences then there are ambiguities in…
Inclusive and semi-inclusive deep inelastic leptoproduction offers possibilities to study details of the quark and gluon structure of hadrons. In many of these experiments polarization is an essential ingredient. We also emphasize the…
In this article, we investigate the contribution of the higher-twist Feynman diagrams to the large-$p_T$ inclusive single meson production cross section in photon-photon collisions and present the general formulas for the higher-twist…
We provide the most general description of the exclusive leptoproduction of a light vector meson, at high center-of-mass energy, within the CGC/shockwave formalism. We keep a twist-3 accuracy in $s$ channel, thus being able to describe all…
I give a short review of the relation of infrared renormalons in QCD and higher twist effects, with the emphasis on possible applications. In particular, I present estimates of renormalon-induced uncertainties in deep inelastic sum rules…
A systematic method of summing the corrections to the renormalon residue arising from higher order renormalons is discussed.
The introduction of a hard singularity in fits to total cross sections and to the ratio of real to imaginary parts enables to reproduce perfectly the data for sqrt(s)< 100 GeV using only simple-pole parametrisations, both for the soft and…
The polarisation of top quarks produced in high energy processes can be a very sensitive probe of physics beyond the Standard Model. The kinematical distributions of the decay products of the top quark can provide clean information on the…
We study deeply virtual Compton scattering on a virtual pion that is emitted by a proton. Using a range of models for the generalized parton distributions of the pion, we evaluate the cross section, as well as the beam spin and beam charge…
In this dissertation we develop a theoretical framework in the context of perturbative QuantumChromoDynamics (pQCD) for studying non-forward scattering processes. In particular, we investigate a non-forward unequal mass virtual Compton…
We give a short overview of recent developments in understanding of the deeply virtual Compton scattering on the proton target.
We discuss specific observables that can be measured in deep inelastic leptoproduction in the case of 1-particle inclusive measurements, namely azimuthal asymmetries and power-suppressed (higher twist) corrections. These quantities contain…
We calculate top pair production and decay at the Tevatron $p\bar p$ collider, with the emission of an extra gluon, and study the corresponding $W+5$\,jet top signals including full spin correlations in the $W \to \ell\nu$ leptonic and…
We computed the leading non-analytic chiral corrections to the generalized parton distributions (GPDs) of the pion and to the two-pion distribution amplitudes. This allows us to obtain the corresponding corrections for the hard exclusive…