Related papers: Future Measurement of the Longitudinal Proton Stru…
From the new measurement of F_L at HERA we derive fixed-Q^2 averages <F_L/F_2>. We compare these with bounds which are rigorous in the framework of the standard dipole picture. The bounds are sharpened by including information on the charm…
This contribution presents recent ZEUS results on proton structure functions at HERA. The inclusive phi(1020)-meson cross section was measured, and it was used to determine the s-quark content of the proton. The structure function F_2 was…
New structure function measurements from fixed target experiments and especially HERA are reviewed. The extraction of parton distributions from these measurements is discussed with special emphasis on systematic problems. Finally the…
Measurements of the diffractive structure function, $F_2^D$, of the proton at HERA are used to extract the partonic structure of the Pomeron. Regge Factorization is tested and is found to describe well the existing data within the selected…
The present status of the measurements of hadronic structure functions of the photon, investigated in deep inelastic electron-photon scattering at LEP, is presented. This article covers the hadronic structure function F_2^gamma of…
The feasibility of measuring parton distribution functions of of virtual photons via the jet production at HERA is investigated.
The parton momentum density distributions in the proton are determined from a next-to-leading order QCD analysis of structure functions measured at HERA and by fixed target experiments. Also included are data on the difference of the up and…
We present a set of formulas to extract the ratio $F_{L}(x,Q^{2})/F_{2}(x,Q^{2})$ and $R(x,Q^{2})$ from the proton structure function parameterized in the next-to-next-to-leading order of the perturbative theory at low $x$ values. The…
Estimates for longitudinal spin asymmetries which single out new polarized nucleon structure functions in deeply inelastic charged current interactions at HERA energies are given, exploiting their interpretation in terms of polarized quark…
A measurement of the longitudinal polarization of the electron beam at HERA utilizing coherent interactions of high energy photons in crystals is proposed. Modification of existing facilities would allow an independent polarization…
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…
Recently the H1 collaboration has published a ``determination'' of the structure function F_L(x,Q^2) at low x. I address the question of how reliable this determination really is. I argue that it is in fact a consistency check of a given…
The structure of the photon is probed in photon-photon interactions at LEP and in photon-proton interactions at HERA.
This contribution covers three recent results on deep-inelastic scattering at HERA: (i) new measurements of the proton longitudinal structure function $F_L$ from H1 and ZEUS experiments, (ii) a dedicated NC cross section measurement from…
We present a set of formulas to extract the longitudinal structure function from the proton structure function and its derivatives with respect to lnQ2 in the next-to-next-to-leading order of the perturbative theory at low x based on a hard…
The electron-proton collider HERA allows the study of the partonic content of the proton in regions of Q-squared up to 50,000 GeV$^2$ and values of Bjorken-x down to 10^-5. This paper presents recent precision measurements of structure…
We constrain the amount of event-by-event fluctuations of the proton by comparing with the HERA coherent and incoherent diffractive $J/\Psi$ production data. We find that the HERA measurements prefer large geometric fluctuations. We then…
A measurement of the derivative (d ln F_2 / d lnx)_(Q^2)= -lambda(x,Q^2) of the proton structure function F_2 is presented in the low x domain of deeply inelastic positron-proton scattering. For 5*10^(-5)<=x<=0.01 and Q^2>=1.5 GeV^2,…
The Mellin-transforms of the next-to-leading order Wilson coefficients of the longitudinal structure function are evaluated.
H1 has measured the diffractive DIS cross section $ep \rightarrow eXY$ using data from both of the HERA data-taking periods. Using new measurements of the diffractive cross section at different centre-of-mass energies, the diffractive…