Related papers: Final States in Photon-Photon and Photon-Proton In…
The exclusive diffractive production of vector mesons and real photons in ep collisions has been studied at HERA in a wide kinematic range. The most recent experimental results are presented.
A review of recent jet measurements of the photon structure from the H1 experiment at HERA. The scale and the virtuality dependence of the effective parton distribution function of the photon is discussed.
Photon-proton ($\gamma p$) interactions with~$Q^2<10^{-2}$~GeV$^2$ and deep-inelastic scattering ($\gamma^* p$) interactions with photon virtualities $Q^2>5$~GeV$^2$ are studied at the high energy electron-proton collider HERA. The…
We present results of calculations of the total and jet photoproduction cross sections at HERA and Fermilab energies$^1$. The calculations take into account the high-energy QCD structure of the photon and are performed for different photon…
Interactions of virtual photons are analyzed in terms of their parton distribution functions. It is shown that the concept of parton distribution functions is phenomenologically very useful even for highly virtual photonds involved in hard…
In this extended analysis using the ZEUS detector at HERA, the photoproduction of isolated photons together with a jet is measured for different ranges of the fractional photon energy, $x_\gamma^{\mathrm{meas}}$, contributing to the…
New preliminary electroweak results from the HERA lepton-proton collider experiments H1 and ZEUS are presented. These include new high Q^2 neutral current cross section measurements and limits on a possible quark radius, in the search for…
Cross sections for elastic and proton-dissociative photoproduction of J/psi mesons are measured with the H1 detector in positron-proton collisions at HERA. The data were collected at $ep$ centre-of-mass energies sqrt{s} approx 318 GeV and…
New experimental results from photoproduction of hadrons at HERA are reviewed.
Ultraperipheral collisions at collider energies are a useful tool to study photon-hadron (proton/nucleus) and photon-photon interactions in a hitherto unexplored energy regime. Theoretical tools to study these processes are briefly…
The charged and neutral pion photoproduction reactions are investigated in a dynamical coupled-channels approach based on the formulation of Haberzettl, Huang, and Nakayama [Phys. Rev. C 83, 065502 (2011)]. The hadronic final-state…
Since the start of HERA operation there has been considerable progress in the understanding of jet production in e p collisions. QCD calculations are now able to accommodate the hadronic structure of the virtual photon. The luminosities…
A review is given on photon-hadron and photon-photon collisions in the ALICE experiment. The physics motivation for studying such reactions is outlined, and the results obtained in proton-lead and lead-lead collisions in Run 1 of the LHC…
Recent results obtained by the HARP collaboration on the measurements of the double-differential production cross-section of positive and negative pions in proton interactions with nuclear targets from Beryllium to Lead are presented. They…
Photon interactions at the LHC result in striking final states with much lower hadronic activity in the central detectors than for pp interactions. In addition, the elastic exchange of a photon leads to a proton scattered at almost…
The high energy photoproduction of jets is being observed at the ep collider, HERA. It may be that the HERA centre-of-mass energy is sufficiently large that the production of more than one pair of jets per ep collision becomes possible,…
Due to the coherence of all the protons in a nucleus, there are very strong electromagnetic fields of short duration in relativistic heavy ion collisions. They give rise to quasireal photon-photon and photon-nucleus collisions with a large…
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…
Deep--inelastic scattering events with a leading baryon have been detected by the H1 experiment at HERA using a forward proton spectrometer and a forward neutron calorimeter. Semi--inclusive cross sections have been measured in the…
The exclusive production of baryon antibaryon pairs in the collisions of two quasi-real photons have been studied in different experiments at e+e- colliders. Results are presented for the processes gamma gamma to proton antiproton and gamma…