Related papers: Timelike Compton Scattering in Ultraperipheral Col…
Exclusive dilepton production occurs with high cross section in gamma-mediated processes at the LHC. The pure QED process $\gamma\gamma\rightarrow\ell^+\ell^-$ provides the conditions to study particle production with masses at the…
The GammaTPC is an MeV-scale single-phase liquid argon time-projection-chamber gamma-ray telescope concept with a novel dual-scale pixel-based charge-readout system. It promises to enable a significant improvement in sensitivity to…
Hard exclusive leptoproduction of real photons from an unpolarized proton target is studied in an effort to elucidate generalized parton distributions. The data accumulated during the years 1996--2005 with the HERMES spectrometer are…
The process of deeply virtual Compton scattering will be shortly introduced, and the latest results from measurements at the HERA ep-collider at DESY will be given. In particular, the cross section has been measured with increased…
We calculate the kinematic twist-3 and 4 corrections to the leading order amplitude of timelike Compton scattering (TCS) on a (pseudo-)scalar target, in the recently developed framework based on the conformal operator-product expansion.…
Dileptons produced during heavy-ion collisions represent a unique probe of the QCD phase diagram, and convey information about the state of the strongly interacting system at the moment their preceding off-shell photon is created. In this…
The inclusion of QCD corrections to the Born amplitude of deeply virtual Compton scattering in both spacelike (DVCS) and timelike (TCS) regimes modifies the extraction process of generalized parton distributions (GPDs) from observables. In…
Gamma-ray bursts (GRBs) are among the most luminous transients in the Universe and constitute prime targets for multimessenger studies, particularly in connection with gravitational-wave events. The detection of very-high-energy (TeV)…
The Common Muon Proton Apparatus for Structure and Spectroscopy (COMPASS) at CERN with its use of beams of naturally polarized muons scattered of a polarized deuteron target, provides an environment of hard scattering between quasi-real…
Coherent hard exclusive reactions on light nuclei provide access to their quark and gluon structure and enable three-dimensional tomography of these complex systems. We study deeply virtual Compton scattering on a helium-4 target, including…
We discuss the mechanisms of photon-photon fusion triggering the dilepton production in proton-proton collisions with rapidity gap in the main detector and one forward proton in the forward proton detectors. This correspond to the LHC…
The influence of the QED-analog of the inverse Compton effect on the transverse momentum spectra of particles produced in proton-proton collisions at energies of \sqrt{s}=14 TeV has been investigated. The analysis is based on the…
The CERN LHC is not only the current energy-frontier collider for parton-parton collisions, but has proven a powerful photon collider providing photon-photon ($\gamma\gamma$) collisions at center-of-mass energies and luminosities never…
The diffractive scattering of photon off proton $\gamma^{(*)} p \to \gamma Y$ (where $Y$ denotes the proton dissociative system or the elastically scattered proton) is measured in two different kinematic regimes at high energy with the H1…
We report on the status of the phenomenological access of generalized parton distributions from photon and meson electroproduction off proton. Thereby, we emphasize the role of HERMES data for deeply virtual Compton scattering, which allows…
Access to Generalised Parton Distributions (GPDs) through Deeply Virtual Compton Scattering (DVCS) is briefly described. Presently available experimental results on DVCS are summarized in conjunction with plans for future measurements.
A measurement is presented of elastic Deeply Virtual Compton Scattering e^+ + p -> e^+ + photon + p at HERA using data taken with the H1 detector. The cross section is measured as a function of the photon virtuality, Q^2, and the invariant…
The study of Generalised Parton Distributions (GPDs) promises to provide new knowl- edge of the structure of the nucleon, including, most notably, access to the total angular momentum of quarks within the nucleon. It can be difficult to…
We investigate lepton-pair production in hard exclusive hadron-hadron collisions. We consider a double handbag (DH) mechanism in which the process amplitude factorizes in hard subprocesses, qq -> qq gamma* and qg -> qg gamma*, and in soft…
We present first measurable predictions for electromagnetic (two-photon) double scattering production of two positron-electron pairs in ultraperipheral heavy-ion collisions at LHC. Measureable cross sections are obtained with realistic cuts…