Related papers: Q2-evolution of parton densities at small-x values
Nuclear parton distributions $f_A(x,Q^2)$ are studied within a framework of the DGLAP evolution. Measurements of $F_2^A/F_2^D$ in deep inelastic $lA$ collisions, and Drell--Yan dilepton cross sections measured in $pA$ collisions are used as…
The charm and beauty quark production in deep inelastic scattering at low values of the Bjorken variable x is considered in the DGLAP improved saturation model. After fitting parameters of the model to the structure function F_2, the heavy…
We perform the fit to the structure function $F_2$ data from HERA including terms due to the resummation at small $x$. The equation for the unintegrated gluon density is solved, previously established within the renormalization group…
The behavior of the gluon distribution of the proton in the low-$x$, low-$Q^2$ domain of deep inelastic electron-proton scattering (DIS) is being investigated. By considering two-gluon exchange as the dominant interaction in the low-$x$,…
Measurements of HERA that explore the parton dynamics at low Bjorken x are presented together with precise determinations of the strong coupling constant alpha_s. Calculations at next to leading order using the DGLAP evolution fail to…
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…
A systematic study is performed of the impact of the various resummed small-$x$ contributions to the anomalous dimensions and coefficient functions on the evolution of unpolarized structure functions in deep-inelastic scattering. The proton…
The longitudinal structure function in deep inelastic scattering is one of the observables from which the gluon distribution can be unfolded. Consequently, this observable can be used to constrain the QCD dynamics at small $x$. In this work…
Using the NMC and E665 nuclear structure function ratios $F_2^A/F_2^D$ and $F_2^A/F_2^{C}$ from deep inelastic lepton-nucleus collisions, and the E772 Drell--Yan dilepton cross sections from proton-nucleus collisions, and incorporating…
The twist--2 contributions to the polarized structure functions in deep inelastic lepton--hadron scattering are calculated including the exchange of weak bosons and using both the operator product expansion and the covariant parton model. A…
$Q^2$ evolution of the structure functions $F_2$ in tin and carbon nuclei is investigated in order to understand recent NMC measurements. $F_2$ is evolved by using leading-order DGLAP, next-to-leading-order DGLAP, and parton-recombination…
It has been found that recent results on forward jet production from deep inelastic scattering can neither be reproduced by models which are based on leading order alpha_s QCD matrix elements and parton showers nor by next-to-leading order…
We show how the operator product expansion evaluated in the approximation of ignoring gluons leads to the covariant formulation of the quark parton model. We discuss the connection with other formulations and show how the free quark model…
We analyse the newest diffractive deep inelastic scattering data from HERA using the dipole model approach. We find a reasonable good agreement between the predictions and the data although the region of small values of a kinematic variable…
An updated next-to-leading order (NLO) QCD analysis of the spin asymmetries A_1^N(x,Q^2) and parton distributions delta f(x,Q^2) in longitudinally polarized deep-inelastic lepton-nucleon scattering is presented within the framework of the…
This talk is a rather sceptical review of our knowledge and understanding of deep inelastic scattering at low x (high energy). We show that the well known success of the DGLAP evolution equations in describing of experimental HERA data…
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…
We formulate the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution of the Deep Inelastic Scattering (DIS) structure functions $F_2$ and $F_{\rm L}$ at next to leading order in $\alpha_s$ (NLO) directly in terms of the structure…
The drastic rise of the proton structure function F_2(x,Q^2) when the Bj\"orken variable x decreases, seen at HERA for a large span of Q^2, negative values for the 4-momentum transfer, may be damped when Q^2 increases beyond several…
We present estimates of possible data on spin-dependent asymmetries in inclusive scattering of high energy polarized electrons by high energy polarized protons at HERA with their statistical errors and discuss systematic errors. We show…