Exclusive J/Ψ,ρ,ϕ and γ production at HERA and LHC within dipole models

We describe exclusive J/ψ,ρ,Φ and γ production at HERA and calculate cross sections and transverse momentum distributions for the incoherent diffractive production of vector mesons J/ψ and γ on heavy nuclei. Within the color dipole approach, we derive the multiple scattering expansion of the incoherent diffractive cross section as an expansion over quasielastic scatterings of the color dipole. We compare our results to the measurement of the ALICE (LHC) collaboration for incoherent J/ψ production

Diffractive Production of Quarkonium in p-A Collisions at LHC

In the present work, we investigated the exclusive diffractive production of charmonium in pronton-nucleus collisions at the Large Hadron Collider (LHC) energies. Such exclusive production reactions possess a cleaner experimental signal than inclusive production once it is characterized by low multiplicity of particles between final produced state and the incident protons of collider beam. The considered theoretical framework was the perturbative model of Quantum Cromodynamics (QCD) for the Pomeron exchange. In particular, we have used the resolved Pomeron model which depends on the Pomeron flux and Pomeron parton distribution functions. The main goal is to provide predictions for the single diffractive cross section for the J/Psi meson production at the energies of 5.02 TeV and 8.8 TeV. We have shown that a measurement is feasible as the order of magnitude is 400 microbarns even absorption corrections. Furthermore, we analyze the ratio of the diffractive to inclusive cross section which allows theoretical uncertainties to be canceled, mostly those associated to approximations performed in inclusive case.

MULTIPARTON COLLISIONS AND HADRON-NUCLEON CROSS SECTIONS

We have ecamined the charged multiplicity distributions arising from p-p and [Formula: see text] at energies ranging from 30 GeV to 1800 GeV. We find that a portion of each distribution does indeed KNO scale. Those parts of the distributions that do not KNO scale are the result of multiparton collisions. Results from E735 at Fermilab seem to show evidence for both double and triple parton-parton collisions. These multiparton collisions seem to account for the increase in the non-single diffractive cross section in this energy domain.

A PARAMETRIZATION OF THE INCLUSIVE DIFFRACTIVE CROSS-SECTION AT HERA

A recently proposed parametrization for the deep inelastic diffractive cross-section is used to describe the H1 '94 data. We find two possible solutions and discuss them in details.