Related papers: Diffractive Photoproduction of Jets with a Direct …
We investigate the effect of a direct pomeron coupling to quarks on inclusive jet production in DIS and photoproduction. The direct pomeron coupling generates a point-like contribution to the diffractive part of the structure function…
We investigate the effect of a direct pomeron coupling to quarks in DIS and photoproduction of jets. The direct pomeron coupling generates a point-like contribution to the diffractive part of the structure function $F_2$, which is analysed…
It is shown that direct photons provide a leading twist mechanism for diffractive jet production in which the jets carry away all of the momentum lost by the proton. Two-photon processes are thus expected to asymptotically dominate…
The diffractive 2-jet production reactions in the proton-proton and lepton-proton processes are discussed. It is shown that they may be very suitable for studying the properties of the pomeron couplings with quarks and hadrons in future…
We investigate the production of a quark-antiquark pair in diffractive photon- proton scattering, approximating soft pomeron exchange by the exchange of two nonperturbative gluons. In deep inelastic scattering at HERA, events with two jets…
Inclusive jet cross sections for events with a large rapidity gap with respect to the proton direction from the reaction $ep \rightarrow jet \; + \; X$ with quasi-real photons have been measured with the ZEUS detector. The cross sections…
The production of prompt photons in photoproduction reactions in the ZEUS experiment is discussed. Cross sections for inclusive prompt photons and for prompt photons accompanied by jets are compared with theory, and the latter are used to…
The production of prompt photons is measured in the photoproduction regime of electron-proton scattering at HERA. The analysis is based on a data sample corresponding to a total integrated luminosity of 340 pb^-1 collected by the H1…
In peripheral relativistic heavy ion collisions at the Large Hadron Collider, jet+jet and photon+jet final states can be produced when a photon from the virtual photon field surrounding the nucleus interacts with a parton in the opposite…
In view of possible photoproduction studies in ultraperipheral heavy-ion collisions at the LHC, we briefly review the present theoretical understanding of photons and hard photoproduction processes at HERA, discussing the production of…
The production of jets is studied in collisions of virtual photons, specifically for applications at HERA. Photon flux factors are convoluted with matrix elements involving either direct or resolved photons and, for the latter, with parton…
In this contribution we study for the first time the prompt photon production in single and double diffractive processes considering the resolved Pomeron model. We estimate the rapidity and transverse momentum dependence of the cross…
We study the photoproduction of isolated prompt photons associated with hadron jets in the framework of the parton Reggeization approach. The cross section distributions in the transverse energies and pseudorapidities of the prompt photon…
Two results in ep physics using HERA data are discussed: a measurement of the effective transverse parton momentum in the proton by studying the production of prompt-photons in photoproduction events in the ZEUS collaboration and…
The photoproduction of isolated photons has been measured in diffractive events recorded by the ZEUS detector at HERA. Cross sections are evaluated in the photon-proton transverse-energy and pseudorapidity ranges 5<ET(gamma)<15 GeV and…
We study a novel property of large rapidity-gap events in deep inelastic scattering at HERA: splitting the pomeron into two jets in the photon-pomeron fusion reaction $\gamma^{*}\Pom \rightarrow q\bar{q}$. It gives rise to the diffraction…
The exclusive diffractive production of vector mesons and real photons in ep collisions has been studied at HERA in a wide kinematic range. Here we present the most recent experimental results together with a Regge-type model. We deduce the…
In this paper we present a detailed comparison of the dijet production by photon -- photon, photon -- pomeron and pomeron -- pomeron interactions in $pp$, $pA$ and ${\rm AA}$ collisions at the LHC energy. The transverse momentum, pseudo --…
The photoproduction of isolated photons has been measured in diffractive events recorded by the ZEUS detector at HERA. Cross sections are evaluated in the photon transverse-energy and pseudorapidity ranges $5 < E_T < 15$ GeV and $-0.7 <…
Diffractive meson production at HERA offers interesting possibilities to investigate diffractive processes and thus to learn something about the properties of the pomeron. The most succesful phenomenological description of the pomeron so…