Related papers: Dipole models and parton saturation in ep scatteri…
Recent results from the HERA ep collider are reviewed in these proceedings. The results are from measurements that probe QCD at high-energy scales, as defined by $Q^2$, the four-momentum-transfer squared of the collisions. These…
Highlights are presented mainly from two recent measurements of the diffractive Deep Inelastic Scattering cross section at HERA. In the first, the process $ep\to eXp$ is studied by tagging the leading final state proton. In the second,…
Using the high energy color dipole approach, we study the exclusive photoproduction of lepton pairs. We use simple models for the elementary dipole-hadron scattering amplitude that captures main features of the dependence on atomic number…
Experimental results obtained with the HERA collider and recent progress in their theoretical interpretation are reviewed. After a short introduction to HERA physics, deep inelastic scattering and photoproduction are discussed as (virtual)…
The Impact-Parameter dependent Saturation Model (IP-Sat) is a simple dipole model that incorporates key features of the physics of gluon saturation and matches smoothly to the perturbative QCD dipole expression at large Q^2 for a given x.…
We investigate the rapidity and transverse momentum distributions of the prompt photon production at the CERN LHC energies considering the current perturbative QCD approaches for this scattering process. Namely, we compare the predictions…
In the recent years we have seen a lot of activity around systems and experiments, like DIS at HERA or the heavy-ion experiments at RHIC, involving a large number of partons due to the high enery and/or the high number of participants of…
Using a momentum space model for the dipole scattering amplitude we present an analysis of the saturation effects at LHC energies, describing the data on proton-proton and proton-lead collisions. The model is based on the asymptotic…
HERA measurements of diffractive ep scattering - the quasi-elastic scattering of the photon in the proton colour field - are summarised. Emphasis is placed on the most recent data.
A parton-shower model for hadronic collisions based on the emission properties of QCD dipoles is proposed. This proposal therefore extends the well-known radiation pattern of pure final-state colour dipoles to QCD initial-state radiation,…
Two-photon exchange (TPE) is one of the leading explanations for discrepancies in measurements of the proton electromagnetic form factors. It has been proposed that TPE could impact not only elastic scattering, but also the cross sections…
We have substantially extended our analysis of the partonic content of the pomeron. Ambiguities in the normalization of the pomeron flux and the possiblity of a direct coupling of the pomeron to single quarks are discussed, yielding two…
The multiplicity structure of the hadronic system X produced in deep-inelastic processes at HERA of the type ep -> eXY, where Y is a hadronic system with mass M_Y< 1.6 GeV and where the squared momentum transfer at the pY vertex, t, is…
The large rapidity gap events, observed at HERA, have changed considerably our physical picture of deep inelastic scattering during the past years. We review the present theoretical understanding of diffractive DIS with emphasis on the…
The parton and hadron cascade model PACIAE 2.1 (cf. Comput. Phys. Commun.184 (2013) 1476) has been upgraded to the new issue of PACIAE 2.2. By this new issue the lepton-nucleon and lepton-nucleus (inclusive) deep inelastic scatterings can…
We show that the `orthogonal' characteristics of the observed rapidity gaps and large forward energy flows in deep inelastic scattering at HERA, can be described within a single framework. Our Monte Carlo model is based on perturbative QCD…
Data from the HERA collider experiments, H1 and ZEUS, have been fundamental to the rapid recent development of our understanding of the partonic composition of the proton and of QCD. This report focuses on inclusive measurements of neutral…
Recent measurements of inclusive and semi-inclusive deep inelastic scattering in electron-proton collisions at HERA are reviewed. These measurements are used to determine the parton distribution functions (PDFs) of the proton, a necessary…
We show that the HERA data for the inclusive structure function F_2(x,Q^2) for x < 0.01 and 0.045 < Q^2 < 45 GeV^2 can be well described within the color dipole picture, with a simple analytic expression for the dipole-proton scattering…
It is shown that charged hadron multiplicity distributions in restricted (pseudo)rapidity intervals in e+e- annihilation and in e+p scattering at HERA are quite well described by the modified negative binomial distribution and its simple…