Observation of Scaling Violations in Scaled Momentum Distributions at HERA

Charged particle production has been measured in deep inelastic scattering (DIS) events over a large range of $x$ and $Q^2$ using the ZEUS detector. The evolution of the scaled momentum, $x_p$, with $Q^2,$ in the range 10 to 1280 $GeV^2$, has been investigated in the current fragmentation region of the Breit frame. The results show clear evidence, in a single experiment, for scaling violations in scaled momenta as a function of $Q^2$.Comment: 21 pages including 4 figures, to be published in Physics Letters B. Two references adde

Once more on electromagnetic form factors of nucleons in extended vector meson dominance model

Extended vector meson dominance model, that allows to describe the electromagnetic form factors of nucleons obeying the asymptotic quark counting rule prescriptions and contains the minimal number of free parameters, is presented. We get a reasonable fit of form factors over experimentally available space-like region of momentum transfer and get also reasonable results in the time-like region.Comment: 7 pages, 2 figure

The Process " Pbar P -> E- E+ " with Polarized Initial Particles and Proton Form Factors in Time-Like Region

The discussion on the asymptotical behaviour of the form factors in the space-like and time-like regions have been corrected and clarified. Fig.3 has been replaced by an improved analysis of the data.Comment: DFTT 13/93. LaTeX file, 11 pages + 3 figures (included

Nucleon form factors: From the space-like to the time-like region

I discuss how dispersion relations can be used to analyse the nucleon electromagnetic form factors, with particular emphasis on the constraints from unitarity and pQCD. Results for nucleon radii, vector-meson couplings, the onset of pQCD and bounds on the strangeness form factors are presented. The em form factors in the time-like region reveal some interesting physics which is not yet understood in full detail. The need for a better data basis at low, intermediate and large momentum transfer and also in the time-like region is stressed.Comment: 11 pp, LaTeX, uses epsf and espcrc1.sty, 6 figures, invited talk, DAPHCE 96, Frascati, November 1996, to appear in the proceedings (Nucl. Phys. A