Related papers: Higher-twist operator effects to parton densities …
We investigate the renormalization of a class of gauge-invariant nonlocal quark bilinear operators, including a finite-length Wilson-line (called Wilson-line operators). The matrix elements of these operators are involved in the recent…
In this paper we investigate the impact of the higher - twist effects, resummed by the non - linear approaches for the QCD dynamics, on the inclusive observables that will be measured in future electron - ion colliders. We assume a…
We present first results for Wilson coefficients of operators up to first order in the covariant derivatives for the case of Wilson fermions. They are derived from the off-shell Compton scattering amplitude $\mathcal{W}_{\mu\nu}(a,p,q)$ of…
This is a talk given at Ringberg Workshop:"New Trends in HERA Physics", 30 May - 4 June, 1999.In this talk we discuss how deeply the region of high parton densities has been studied experimentally at HERA. We show that the measurements of…
Reliable knowledge of parton distributions at large x is crucial for many searches for new physics signals in the next generation of collider experiments. Although these are generally well determined in the small and medium x range, it has…
The anomalous dimensions of high-twist operators in deeply inelastic scattering ($\gamma_{2n}$) are calculated in the limit when the moment variable $N \rightarrow 1$ (or $x_B\rightarrow 0$) and at large $Q^2$ (the double logarithmic…
In the first part of this talk, I will summarize recent developments in the study of the chiral-odd spin-dependent parton distributions h_1(x,Q^2) and h_L(x,Q^2) of the nucleon, in particular, (i) Next-to- leading order Q^2 evolution of…
We investigate the influence of higher twist corrections to deep inelastic structure functions in the low-$Q^2$ and small-$x$ HERA region. We review the general features of the lowest-order QCD diagrams which contribute to twist-4 at…
We verify the operator product expansion (OPE) of deep inelastic scattering (DIS) on the lattice and present first results of a non-perturbative calculation of the Wilson coefficients.
We calculate all twist-two, three and four parton distribution functions involving two quark correlations using the wavefunction of the MIT bag model. The distributions are evolved up to experimental scales and combined to give the various…
We present the first results of a new global next-to-leading order analysis of spin-dependent parton distribution functions from the most recent world data on inclusive polarized deep-inelastic scattering, focusing in particular on the…
A sensitivity of twist-4 and $\alpha_s$ values extracted in the NLO QCD analysis of nonsinglet SLAC-BCDMS-NMC deep inelastic scattering data to the choice of QCD renormalization scale (RS) is analysed. It is obtained that the high twist…
We show that the ratio of different structure functions have a maximum which depends on energy. We argue, using Golec-Biernat and Wusthoff model, that these maxima are the certain functions of the saturation scale. The analysis of leading…
Deep-inelastic scattering at small x is a new field of QCD phenomenology which HERA experiments started to explore. The data show the feature expected by the perturbative Regge asymptotics. We describe the parton picture of structure…
The jet parton correlation has been studied for different cut scenarios and various jet algorithms. These migrations are getting important for measuring the strong coupling constant alpha_s and the NLO gluon density g(xi,Q^2) from jet rates…
Recently, the ZEUS collaboration has reported on several remarkable properties of events with a large rapidity gap in deep inelastic scattering. We suggest that the mechanism underlying these events is the scattering of electrons off lumps…
The QCD expectations concerning the deep inelastic lepton - hadron scattering at low $x$ and their phenomenological implications for HERA are summarised. Theoretical predictions for the structure function $F_2(x,Q^2)$ based on the leading…
We perform next-to-leading order global analyses of deep inelastic and related data for different fixed values of $\alpha_S (M_Z^2)$. We present sets of parton distributions for six values of $\alpha_S$ in the range 0.105 to 0.130. We…
We study the consistency of parton distribution functions in the presence of target mass corrections (TMCs) at low Q^2. We review the standard operator product expansion derivation of TMCs in both x and moment space, and present the results…
The results of a recent next-to-leading order QCD analysis of the world data on polarized deep inelastic scattering are reported. New parameterizations are derived for the quark and gluon distributions, accounting for the massive Wilson…