Related papers: Does the ``Soft Pomeron'' Cope with the HERA Data?
Studies of hadron production in proton-proton collisions, including charged particle transverse momentum, pseudo-rapidity and event-by-event multiplicity distributions at \sqrt{s} = 0.9, 2.36 and 7 TeV are shown. Measured spectra of…
We present predictions for the exclusive and dissociative production of vector mesons off protons in an electron-ion collider. The computation is based on the energy-dependent hot spot model that has successfully described the available…
A recently developed model for $\rho$-meson propagation in dense hadronic matter is applied to total photoabsorption cross sections in $\gamma$-proton and $\gamma$-nucleus reactions. Within the vector dominance model the photon coupling to…
Recent results on diffraction at HERA, from the H1 and ZEUS Collaborations, and at Tevatron, from the CDF and D0 Collaborations, are reviewed. The measurement of the diffractive structure function at HERA is presented, and the pomeron…
The exclusive electroproduction of J/psi mesons, ep->epJ/psi, has been studied with the ZEUS detector at HERA for virtualities of the exchanged photon in the ranges 0.15<Q^2<0.8 GeV^2 and 2<Q^2<100 GeV^2 using integrated luminosities of 69…
The ZEUS data on the charm structure function F_2^c at small x fit well to a single power of x, corresponding to the exchange of a hard pomeron that is flavour-blind. When combined with the contribution from the exchange of a soft pomeron,…
The electroproduction of rho mesons is studied at HERA with the H1 detector at high Q^2 and high |t|. Cross sections are measured as a function of Q^2, W and t. The W dependence of the gamma*-p cross section is observed to increase with Q^2…
Recent results on the Deeply Virtual Compton Scattering (DVCS) and prompt photon productions from H1 and ZEUS experiments on the $ep$ collider HERA are presented. A new DVCS cross section measurements of the H1 Collaboration, for photon…
An earlier developed model for vector meson photoproduction, based on a dipole Pomeron exchange, is extended to electroproduction. Universality of the non linear Pomeron trajectory is tested by fitting the model to ZEUS and H1 data as well…
We present and discuss two different topics where Tevatron and HERA data can be compared directly. A method allowing for a direct comparison of data with theoretical predictions is proposed for forward jet production at HERA. An application…
A model based on a dipole Pomeron framework for vector meson exclusive photoproduction by real and virtual photons shows very good agreement with the experimental data. The model does not violate unitarity constrains and describes in a…
This article gives an overview of recent highlights from experimental measurements of heavy-ion collisions at ultra-relativistic energies: Measurements of electroweak probes constrain both the initial collision geometry and the nuclear…
Inclusive distributions of soft production of mesons in hadronic collisions are calculated in the valon-recombination model. The new determination of the valon distributions from hard scattering data makes possible a tightly interrelated…
In this paper we discuss coherent photo- and leptoproduction of vector mesons from deuterons at intermediate (virtual) photon energies, 3 < nu < 30 GeV. We consider the scattering from unpolarized and polarized targets as well as processes…
In the present paper we address double parton scattering (DPS) in quasi-real photon-proton interactions. By using electromagnetic and hadronic models of the photon light cone wave functions, we compute the so-called effective cross-section,…
At the electron-proton collider HERA the inclusive $D^{*\pm}$ meson photoproduction cross section has been measured with the H1 detector in two different, but partly overlapping, kinematical regions. For the first, where $<W_{\gamma p}>…
The structure of real and virtual photons has been studied in ep collisions at HERA using dijet production. Measurements of differential dijet cross sections as function of the fraction of photon's momentum invested in the dijet system are…
Interactions of virtual photons are analyzed in terms of photon structure. It is argued that the concept of parton distribution functions is phenomenologically very useful even for highly virtual photons involved in hard collisions. The…
A formalism for hadron production at high \pt in heavy-ion collisions has been developed such that all partons hadronize by recombination. The fragmentation of a hard parton is accounted for by the recombination of shower partons that it…
Recent results, obtained by the H1 and ZEUS collaborations, are presented on differential cross sections, for inclusive prompt photon production in DIS and for photoproduction of prompt photons accompanied by a hadronic jet. Also presented…