Related papers: Q^2 evolution studies of nuclear structure functio…
The HERA data on the proton structure function, $F_2(x,Q^2)$, at very small $x$ and $Q^2$ show the dramatic departure of the logarithmic slope, $\partial F_2/\partial\log Q^2$, from theoretical predictions based on the DGLAP evolution. We…
Deep inelastic structure functions $F_2^A(x)$ are investigated in a $Q^2$ rescaling model with parton recombination effects. We find that the model can explain experimentally measured $F_2^A(x)$ structure functions reasonably well in the…
QCD predictions on the low-$x$ behaviour of the structure functions are reviewed and compared with the recent measurements of $F_2(x,Q^2)$ at HERA. The present theoretical accuracy of these predictions is discussed.
Preliminary results on a measurement of the proton structure function F_2 are reported for momentum transfers squared Q^2 between 1.5~GeV^2 and 5000 GeV^2 and for Bjorken x between 5.10^{-5} and 0.32 using data collected by the HERA…
I investigate what a direct measurement of the longitudinal structure function F_L(x,Q^2) could teach us about the structure of the proton and the best way in which to use perturbative QCD for structure functions. I assume HERA running at a…
Using recently derived relations between spin-dependent nuclear and nucleon g_1 and g_2 structure functions at finite Q^2, we study nuclear effects in 3He in the nucleon resonance and deep inelastic regions. Comparing the finite-Q^2 results…
A precise proton structure function F_2 at low x is measured. The data is interpreted in the framework of QCD with an extraction of gluon density xg. The charm contribution to F_2 is determined in an extended kinematic range. Neutral and…
The differences are discussed between various next-to-leading order prescriptions for the QCD evolution of parton densities and structure functions. Their quantitative impact is understood to an accuracy of 0.02\%. The uncertainties due to…
Recent results from the HERA experiment H1 on the longitudinal stucture function $F_{L}$ of the proton are presented. They include proton structure function analyses with particular emphasis on those kinematic regions which are sensitive to…
The structure function $g_1(x,Q^2)$ is analysed within the formalism based on unintegrated spin dependent parton distributions incorporating the LO Altarelli-Parisi evolution and the double $ln^2(1/x)$ resummation at low $x$. We…
The strikingly different high energy behaviours of real photoabsorption cross-sections with Q^2 = 0 and the low x proton structure function at large Q^2 are studied from a laboratory frame viewpoint, in which the x and Q^2 dependence…
The CKMT model for the nucleon structure function F_2 is in good agreement with the HERA data at low and moderate Q^2. The fit to the same data obtained with a modified version of the model in which a logarithmic dependence on Q^2 has been…
Nuclear modification of the structure function $F_3$ is investigated. Although it could be estimated in the medium and large $x$ regions from the nuclear structure function $F_2^A$, it is essentially unknown at small $x$. The nuclear…
The recent $F_2$ data can be described using the DGLAP evolution equations with an appropriate choice of input distributions and the choice of the starting scale for the $Q^2$ evolution. We demonstrate in this paper that we cannot conclude…
The $n$-th moments of the nuclear structure function $F_2^A(x,Q^2)$ are analyzed using the off-shell kinematics appropriate to describe deep inelastic electron-nucleus scattering within the impulse approximation. It is shown that off-shell…
In this talk I review the low x QCD experimental results from HERA and their theoretical underpinnings. In particular, I discuss the structure function $F_2$, large rapidity gap events, pomeron structure functions and $J/\psi$ production.
Q$^2$ variation of the nuclear-structure-function ratio $F_2^A(x,Q^2)/F_2^D(x,Q^2)$ is investigated in a parton model with Q$^2$-rescaling and parton-recombination effects. Calculated results are compared with the NMC (New Muon…
In the framework of conventional Regge theory we present a common description of total photon-proton cross-section and proton structure functions in the region $0 \leq Q^2 \leq 5 \ {\rm GeV}^2$. Using it as an initial condition in the…
We study the global Q^2 dependence of large x, F_2 nucleon structure function data, with the aim of providing a perturbative-QCD based, quantitative analysis of parton-hadron duality. As opposed to previous analyses at fixed x, we use a…
The $Q^2$ dependence of the ratios of nuclear structure functions $F_2^A$ is studied by performing QCD evolution of nuclear parton distribution functions. The log $Q^2$ slope of these ratios is very sensitive to the nuclear gluon…