Related papers: New Structure Function Results at Low x and High Q…
The charm contribution to the proton structure, F_2^c(x,Q^2), is determined using the inclusive cross sections of D*(2010) meson production in deep-inelastic scattering. The cross section measurement covers the region 5 < Q2 < 1000 GeV2 in…
Results are presented of a study of the experimental and theoretical accuracy one may achieve at HERA in measuring the strong coupling constant alpha_s and the gluon distribution from scaling violations of F2 structure functions.
Recent HERA low $Q^2$ data show that the logarithmic slope of the protonstructure function ($\frac{\partial F_2}{\partial \ln Q^2}$) is significantly different from perturbative QCD expectations for smallvalues of $Q^2$ at exeedingly small…
We pursue the hypothesis that the events with a large rapidity gap, observed at HERA, reflect the scattering of electrons off lumps of wee partons inside the proton. A simple scaling behaviour is predicted for the diffractive structure…
We study the perturbative QCD description of the HERA measurements of $F_2 (x, Q^2)$ using a gluon distribution that is obtained from an evolution incorporating angular ordering of the gluon emissions, and which embodies both GLAP and BFKL…
First measurements are presented of the diffractive cross section $\sigma_{ep \rightarrow eXY}$ at centre-of-mass energies $\sqrt{s}$ of 225 and 252 GeV, together with a precise new measurement at $\sqrt{s}$ of 319 GeV, using data taken…
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…
It is shown that recent small-x measurements of the photon structure function F_2^{\gamma}(x,Q^2) by the LEP-OPAL collaboration are consistent with parameter-free QCD predictions at all presently accessible values of Q^2.
We study inclusive electroproduction on the proton at low $x$ and low $Q^2$ using a soft and a hard Pomeron. The contribution of the soft Pomeron is based on the Stochastic Vacuum Model, in which a nonperturbative dipole-dipole cross…
A new measurement of the inclusive DIS ep cross section using H1 data from the year 2000 is performed and combined with published results using 1996/97 data. The new data covers the region of Q2 from 12 to 150 GeV2 at HERA with…
The inclusive single and double differential cross-sections for neutral and charged current processes with four-momentum transfer squared Q^2 between 150 and 30,000 GeV2 and with Bjorken x between 0.0032 and 0.65 are measured in e^+ p…
Measurements are presented of inclusive charm and beauty cross sections in e^+p collisions at HERA for values of photon virtuality 12 \le Q^2 \le 60 GeV^2 and of the Bjorken scaling variable 0.0002 \le x \le 0.005. The fractions of events…
I review recent developments in the study of the low-x partonic content of protons and nuclei, with a focus on the latter, as one expects possible deviations from linear QCD evolution to be most pronounced in that case. I give examples of…
The current status of measurements of the nucleon structure functions and their understanding is reviewed. The fixed target experiments E665, CCFR and NMC and the HERA experiments H1 and ZEUS are discussed in some detail. The extraction of…
Recent results of open charm and beauty production in electron proton scattering at HERA are presented. In photoproduction, the measured cross sections for charm exceed fixed order NLO QCD calculations. Experimental evidence supports the…
We predict the effect of the charm structure function on the longitudinal structure function at small x. In NLO analysis we find that the hard Pomeron behavior gives a good description of $F_{L}$ and $F^{c}_{k}$ (k = 2,L) at small x values.…
Results on the derivative of log(F_2) with respect to log(x) at fixed Q^2 are presented. The measured derivatives are within errors independent of x for Q^2 >= 0.85 GeV^2 and increase linearly with log(Q^2) for 0.0001 <= x <= 0.01 and Q^2…
In this article we present a review of the structure of the proton and the current status of our knowledge of the parton distribution functions (PDFs). The lepton-nucleon scattering experiments which provide the main constraints in PDF…
We present our QCD analysis of the proton structure function $F_2^p(x,Q^2)$ to determine the parton distributions at the next-to-leading order (NLO). The heavy quark contributions to $F_2^i(x,Q^2)$, with $i$ = $c$, $b$ have been included in…
We review recent HERA data on the structure function F_2 at small x and large Q^2. We show that the salient features of the data are revealed by comparing them to the double asymptotic scaling behaviour which F_2 is predicted to satisfy in…