Related papers: Virtual Photon Structure from Jet Production at HE…
High energy multiparticle photoproduction off nuclear targets is studied. The photon is assumed to interact in direct scattering processes or as a resolved $q\bar{q}$-state according to the Generalized Vector Dominance Model. In the…
The production of $D^{*\pm}$ mesons in deep inelastic $ep$ scattering has been measured for exchanged photon virtualities $ 5<Q^2<1000 \gev^2 $, using an integrated luminosity of 363 pb$^{-1}$ with the ZEUS detector at HERA. Differential…
A measurement of the inclusive cross-section for the photoproduction of protons in the central fragmentation region at HERA is presented. The measured cross-section is compared with the prediction of the PYTHIA MC model. The obtained value…
We investigate the prompt photon photoproduction at HERA within the framework of kt-factorization QCD approach. Our consideration is based on the off-shell matrix elements for the underlying partonic subprocesses. The unintegrated parton…
We calculate production rates for several hard processes in ultraperipheral proton-nucleus and nucleus-nucleus collisions at the LHC. The resulting high rates demonstrate that some key directions in small $x$ research proposed for HERA will…
We propose to measure valence-quark shadowing by observing charged pion productions in electron-nucleus scattering at HERA. Studies of shadowing phenomena in the valence-quark distribution could be useful in discriminating among various…
Hadronic antenna patterns can provide a valuable diagnostic tool for probing the origin of the apparent excess of high $x,Q^2$ events at HERA. We present quantitative predictions for the distributions of soft particles and jets in standard…
Results on elastic electroproduction of rho mesons are presented for a photon virtuality in the range 1 < Q^2 < 60 GeV^2 and for a hadronic centre of mass energy in the range 30 < W < 140 GeV. The shape of the (pi pi) mass distribution is…
In this contribution we present the main results of the investigation about double parton scattering (DPS) in quasi-real photon-proton interactions. We show the first evaluation of the DPS cross-section at leading-order for the four-jet…
Differential dijet cross sections are measured in photoproduction in the region of photon virtualities Q^2 < 1 GeV^2 with the H1 detector at the HERA ep collider using an integrated luminosity of 66.6 pb^{-1}. Jets are defined with the…
A systematic multiple scattering formalism for vector meson electroproduction from nuclei is developed, with emphasis on the formation, propagation and hadronization scales for quark-gluon fluctuations of the virtual high-energy photon. The…
New results on elastic electroproduction and proton-dissociative photoproduction at large t of rho, phi and J/psi mesons are presented. They are interpreted within perturbative QCD.
I discuss few selected topics in heavy flavour photoproduction at HERA which require large integrated luminosity in order to be experimentally investigated. I present phenomenological predictions for bottom production. As a possible…
The parton momentum density distributions in the proton are determined from a next-to-leading order QCD analysis of structure functions measured at HERA and by fixed target experiments. Also included are data on the difference of the up and…
In this short report, we discuss the Jet Physics results and perspectives at HERA, Tevatron and LHC.
Triple differential dijet cross sections in e^\pm p interactions are presented in the region of photon virtualities 2<Q^2<80GeV^2, inelasticities 0.1<y<0.85, jet transverse energies E_T1>7GeV, E_T2>5GeV, and pseudorapidities -2.5 < eta_1^*,…
The inclusive photoproduction of D\ast mesons and of D\ast-tagged dijets is investigated with the H1 detector at the ep collider HERA. The kinematic region covers small photon virtualities Q2 < 2 GeV2 and photon-proton centre-of-mass…
A review is presented of jet substructure measurements from the H1 and ZEUS Collaborations at HERA. The results presented include tests of perturbative QCD, comparison of the properties of quark and gluon jets, the comparison of the pattern…
Prompt photons, together with an accompanying jet, have been studied in the photoproduction regime of ep scattering with the ZEUS detector at HERA. Predictions based on leading-logarithm parton-shower Monte Carlo models and…
The production of isolated photons in deep-inelastic scattering $ep\to e \gamma X$ is measured with the H1 detector at HERA. The measurement is performed in the kinematic range of negative four-momentum transfer squared $4<Q^2<150 $~GeV$^2$…