Monte Carlo calculations for the hard Pomeron

Starting from the same input as the standard BFKL Pomeron, we directly calculate the ``hard'' Pomeron as a gluonic ladder by using Monte Carlo methods. We reproduce the characteristic features of the the BFKL Pomeron and are now also able to evaluate new observables. The applicability of the BFKL approach under realistic kinematical conditions can be tested and the influence of the running coupling constant examined.Comment: 9 pages and 4 figures included. To appear in Phys.Lett.

Production of vector mesons by real and virtual photons at high energies

A model based on Reggeon field theory is used for the description of the photo- and electroproduction of vector mesons ($\rho^0, \omega, \phi, J /\psi$) on the proton. Its main feature is the dependence of the Pomeron intercept on the virtuality of the photon. The few parameters of the model were determined by fitting the total cross sections for real and virtual photons on the proton. This allows a parameter-free description of the energy dependence of vector meson production. Very good agreement with the existing high energy data is obtained.Comment: 6 pages and 3 figures included in a uuencoded fil

Charm Contribution to the Structure Function in Diffractive Deep Inelastic Scattering

The charm contribution to the structure functions of diffractive deep inelastic scattering is considered here within the context of the Ingelman-Schlein model. Numerical estimations of this contribution are made from parametrizations of the HERA data. Influence of the Pomeron flux factor is analized as well as the effect of the shape of the initial parton distribution employed in the calculations. The obtained results indicate that the charm contribution to diffractive deep inelastic process might be large enough to be measured in the HERA experiments.Comment: 16 pages, RevTeX, 6 figures, to be published in Physical Review