Related papers: The Longitudinal Structure Function at HERA
The prediction of FL(x,Q2)=0.27F2(x,Q2) in the color-dipole picture based on color-transparency and transverse-size reduction, is consistent with the experimental results from HERA.
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…
The elastic production of vector mesons at HERA is discussed from the theoretical point of view. We briefly review different models, their successes and shortcomings. Main emphasis is put on recent issues in perturbative QCD calculations.…
Experimental results on hadronic structures are discussed in view of our physics understanding. Achievements and challenges are noted.
The upper bound on the ratio of the proton structure functions $F_L/F_2$ tested in the recent paper "The New $F_L$ Measurement from HERA and the Dipole Model", contrary to what is said therein, does not provide a model-independent…
An overview is given of the ongoing measurement at HERA of the parton structure of the photon, as a function of its virtuality. Preliminary ZEUS results show disagreement with an NLO QCD calculation.
The first measurements of the longitudinal proton structure function FL in deep inelastic positron-proton scattering at low Bjorken x are described. Theoretical predictions in higher order QCD and using dipol model calculations are…
Recent measurement of inclusive processes and hadronic final states in diffractive deep-inelastic scattering at HERA are used to investigate the QCD factorisation properties and study partonic structure of colour singlet exchange. Resolved…
A recently proposed parametrization for the deep inelastic diffractive cross section is used to describe the H1 94 data. We find two possible solutions, and we discuss them is some detail.
We show that recent data from HERA on the proton structure function $F_2$ at small $x$ and large $Q^2$ provide a direct confirmation of the double asymptotic scaling prediction of perturbative QCD. A linear rise of $\ln F_2$ with the…
A review of theoretical models of diffractive structure functions in deep inelastic scattering (DIS) is presented with a view to highlighting distinctive features, that may be distinguished experimentally. In particular, predictions for the…
New properties of the multiplicity distributions predicted by higher order QCD and their physical origin are discussed briefly. Several studies which can be performed at HERA are proposed.
A number of internal inconsistencies, misleading conclusions and lack of completeness in the analyses of the small $x$ deep inelastic data in recent papers of HERA physicists, particularly in a very recent one by the H1 collaboration are…
I present a concise review of the possible evidence for new physics at HERA and of the recent work towards a theoretical interpretation of the signal. It is not clear yet if the excess observed at large Q^2 is a resonance or a continuum…
We review recent results on diffraction at HERA and discuss their interpretation in the perturbative and non-perturbative regimes.
We compare recent experimental results for one-particle-inclusive processes in deeply inelastic scattering at HERA with theoretical predictions in next-to-leading-order QCD perturbation theory, and study the factorization scale dependence…
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 status of the resummation of small x contributions to the unpolarized and polarized deep inelastic structure functions is reviewed.
A first measurement is reported of the longitudinal proton structure function F_L(x,Q^2) at the ep collider HERA. It is based on inclusive deep inelastic e^+p scattering cross section measurements with a positron beam energy of 27.5 GeV and…
The results for structure function $F_L$, obtained in the $k_T$-factorization and collinear approaches, are compared with recent H1 experimental data at fixed $W$ values.