Aspects of Higgs Production at the LHC

We discuss the main features and predictions of the GLMM model, which is based on a QCD motivated theoretical approach, and successfully describes the experimental data on total, elastic and diffractive cross sections. In addition we calculate the survival probability for a SM Higgs at the LHC, and compare our results with those of the Durham group.Comment: 7 pages, 4 figures, talk at 13th International Confernce on Elastic and Diffractive Scattering, CERN, 29th June - 3rd July 200

QCD Saturation and Soft Processes

We show that an approximate solution to the amended non-linear Balitsky-Kovchegov evolution equation which was formulated for hard QCD processes, can be extended to provide a good description of photoproduction and soft hadronic (non perturbative) reactions.Comment: 3 pages, 4 Postscript figures, Contribution to the Proceedings of the International European Conference on High Energy Physics EPS (July 17-23, 2003) Aachen, German

EFFECTS OF SHADOWING IN DOUBLE POMERON EXCHANGE PROCESSES

The effects of shadowing in double Pomeron exchange processes are investigated within an eikonal approach with a Gaussian input. Damping factors due to screening are calculated for this process and compared with the factors obtained for total, elastic and single diffraction cross sections. Our main conclusion is that counting rate calculations, of various double Pomeron exchange processes (without screening corrections) such as heavy quark and Higgs production are reduced by a factor of 5 in the LHC energy range, when screening corrections are applied.Comment: 9 pages, latex, 5 figures obtainable from author

Behaviour of the forward peak in hard diffractive leptoproduction of vector mesons

The measured forward slope in elastic and inelastic leptoproduction of vector mesons differ by a substantial amount. In an attempt to describe this phenomenon we construct a two radii model for the target proton, and estimate the effective parameters of the hard Pomeron obtained from a pQCD dipole model with eikonal shadowing corrections (SC). We show that the SC reduce the intercept of the hard Pomeron and generate an effective shrinkage of the forward peak and a diffractive dip at $|t| \approx 1 GeV^2$, which appears to affect the value of the experimentally measured slope.Comment: 18 pages, 7 figures, one table, everything in tar.gz fil

The Role of Screening Corrections in High Energy Photoproduction

The role of screening corrections, calculated using the eikonal model, is discussed in the context of soft photoproduction. We present a comprehensive calculation considering the total,elastic and diffractive cross sections jointly. We examine the differences between our results and those obtained from the supercritical Pomeron-Reggeon model with no unitarity corrections.Comment: 12 pages (Replacement due to PostScript file problem in previous posting

Survival probability of large rapidity gaps in QCD and N=4 SYM motivated model

In this paper we present a self consistent theoretical approach for the calculation of the Survival Probability for central dijet production . These calculations are performed in a model of high energy soft interactions based on two ingredients:(i) the results of N=4 SYM, which at the moment is the only theory that is able to deal with a large coupling constant; and (ii) the required matching with high energy QCD. Assuming, in accordance with these prerequisites, that soft Pomeron intercept is rather large and the slope of the Pomeron trajectory is equal to zero, we derive analytical formulae that sum both enhanced and semi-enhanced diagrams for elastic and diffractive amplitudes. Using parameters obtained from a fit to the available experimental data, we calculate the Survival Probability for central dijet production at energies accessible at the LHC. The results presented here which include the contribution of semi-enhanced and net diagrams, are considerably larger than our previous estimates.Comment: 11 pages, 10 pictures in .eps file