Related papers: The Longitudinal Structure Function $F_L$ at small…
We calculate the contribution from the $q \bar q g$ state production to the diffractive cross sections in deep inelastic scattering at high energy. The obtained cross section is finite by itself and a part of the full next-to-leading order…
It is shown that a Bessel-like behaviour of the structure function F2 at small x, obtained for a flat initial condition in the DGLAP evolution equations, leads to good agreement with the deep inelastic scattering experimental data from…
The higher twist contributions to the deeply inelastic structure functions $F_2^{p}(x,Q^2)$ and $F_2^{d}(x,Q^2)$ for larger values of the Bjorken variable $x$ are extracted extrapolating the {twist--2} contributions measured in the large…
We derive an expression for diffractive F_2 structure function which should be valid at small x for quasi-elastic scattering on a hadron and for quasi-elastic scattering on a large nucleus. This expression includes multiple rescatterings of…
We show that a unified approach to the perturbative evolution of structure functions which sums all logarithms of Q^2 and 1/x at leading and next-to-leading order yields results in full agreement with the 1993 HERA data for F_2. This makes…
The results of a measurement of the proton structure function F_2(x,Q^2)and the virtual photon-proton cross section are reported for momentum transfers squared Q^2 between 0.35 GeV^2 and 3.5 GeV^2 and for Bjorken-x values down to 6 10^{-6}…
In this paper, we prove a large deviation principle of Freidlin-Wentzell's type for the multivalued stochastic differential equations. As an application, we derive a functional iterated logarithm law for the solutions of multivalued…
We perform a numerical study of the QCD corrections to the structure function $F_L(x,Q^2)$ in the HERA energy range. The $K$--factors are of $O(30%)$ and larger in parts of the kinematic range. The relative corrections to…
We present the order $\alpha_s^2$ contributions to the coefficient functions corresponding to the longitudinal fragmentation function $F_L(x,Q^2)$. A comparison with the leading order $\alpha_s$ result for $F_L(x,Q^2)$ shows that the…
We calculate the perturbative component of the DIS structure function F_1 singlet in the Double-Logarithmic Approximation (DLA) and account at the same time for the running QCD coupling effects. By constructing and solving evolution…
We present a calculation of the reduced cross section in momentum-space approach utilizing the Block-Durand-Ha (BDH) parameterization of the proton structure function $F_{2}(x,Q^2)$ and the leading-order (LO) longitudinal structure function…
We calculate DIS-scheme splitting and coefficient functions for electromagnetic deep inelastic scattering with small x resummations, as given by the NLL BFKL equation with running coupling and approximate NLL resummed impact factors. The…
We show that the double asymptotic scaling of the HERA structure function data is consistent with pre-HERA data at larger $x$, soft pomeron behaviour at small $x$ and a sensible starting scale $Q_0$. We can thus actually calculate $F_2^p$…
It is shown that the previously noted extreme perturbative instability of the longitudinal structure function F_L(x,Q^2) in the small Bjorken-$x$ region, is a mere artefact of the commonly utilized `standard' gluon distributions. In…
A summary is given on the main aspects which were discussed by the working group. They include new results on the deep inelastic scattering structure functions $F_2, xF_3, F_L$ and $F_2^{c\bar{c}}$ and their parametrizations, the…
We critically examine the QCD predictions for the $Q^2$ dependence of the electron-proton deep-inelastic structure function $F_2(x,Q^2)$ in the small $x$ region, which is being probed at HERA. The standard results based on next-to-leading…
We show that the diffractive structure function is perturbatively calculable in the domain where the diffractive mass is small but still outside the resonance region. In this domain, which can be characterized by Lambda^2/Q^2 << 1-beta <<…
Diffractive parton distributions of the proton are determined from fits to diffractive data from HERA. In addition to the twist--2 contribution, the twist--4 contribution from longitudinally polarised virtual photons is considered, which is…
The transverse size of q q-bar fluctuations of the longitudinal photon is reduced relative to the transverse size of q q-bar fluctuations of the transverse photon. This implies R(W2, Q2) = 0.375 or, equivalently, FL/F2 = 0.27 at x<<0.1 and…
The gluon contributions to $F_L(x,Q^2)$ in ${\cal O}(\alpha_s)$ are calculated taking into account the transverse momentum of the initial state parton. In comparison with collinear factorization $F_L(x,Q^2)$, is not affected at large $x$…