Related papers: Study of elementary reactions with the HADES diele…
We discuss the status of calculating in-medium modifications of vector-meson spectral functions in hot and dense matter, their application to dilepton spectra in ultrarelativistic heavy-ion collisions, and possible relations to chiral…
Charged particle production in deep-inelastic ep scattering is measured with the H1 detector at HERA. The kinematic range of the analysis covers low photon virtualities, 5 < Q^2 < 100 GeV^2, and small values of Bjorken-x, 10^{-4} < x <…
The initial collision geometry, including the reaction plane, is crucial for interpreting collective phenomena in relativistic heavy-ion collisions, yet it remains experimentally inaccessible through conventional measurements. Recent…
We discuss photon-photon fusion mechanisms of dilepton production in proton-proton collisions with rapidity gap in the main detector and one forward proton in the forward proton detectors. This is relevant for the LHC measurements by…
A search for events containing two or more high-transverse-momentum isolated leptons has been performed in ep collisions with the ZEUS detector at HERA using the full collected data sample, corresponding to an integrated luminosity of 480…
We study the effect of in-medium hadronic properties in photon nucleus interactions in the context of shadowing as well as the dilepton spectrum for incident photon energies in the range 1.1- 3 GeV. A reasonable agreement with the…
One principal motivation for studying exclusive reactions is that they provide a new class of observables, called off-diagonal parton distributions, for the internal structure of the nucleon. The study of exclusive reactions provides a…
The production of dielectrons in reactions involving a_1 mesons and pions is studied. We compare results obtained with different phenomenological Lagrangians that have been used in connection with hadronic matter and finite nuclei. We…
Measurements of open charm hadro-production from CERN and Fermilab experiments are reviewed, with particular emphasis on the absolute cross sections and on their A and sqrt(s) dependences. Differential pt and xf cross sections calculated…
The properties of electromagnetic radiation from hot fireballs as created in ultra-relativistic heavy-ion collisions are reviewed. We first outline how the medium effects in the electromagnetic spectral function, which governs thermal…
We consider production of dilepton pairs through coherent electro-magnetic radiation during nuclear collisions. We show that the number of pairs produced through bremsstrahlung is about two orders of magnitude smaller than the yield…
The HADES experiment provides a large acceptance combined with a high mass resolution and therefore makes it possible to study dielectron and hadron production in heavy-ion collisions with unprecedented precision. With the high statistics…
Dielectron production in reactions $\pi^- p \rightarrow n e^+e^-$ and $\pi^- p \rightarrow n e^+e^- \gamma$ at energies less than 1 GeV is studied assuming electron-positron pair production to occur in the virtual time-like photon splitting…
The production of the low-mass dielectrons is considered to be a powerful tool to study the properties of the hot and dense matter created in the ultra-relativistic heavy-ion collisions. We present the preliminary results on the first…
We study Pb+Pb collisions at 158 A GeV/c using a hydrodynamical approach. We test different equations of state (EoSs) and different initial conditions and show that there are more than one initial state for each EoS which reproduce the…
We investigate hadron attenuation in deep-inelastic lepton scattering off complex nuclei in the kinematic regime of the HERMES experiment. Our transport theoretical simulations reveal strong prehadronic final state interactions of the…
The reaction $ pp \to pp \eta \to pp \gamma e^+ e^-$ is discussed within a covariant effective meson-nucleon theory. The model is adjusted to data of the subreaction $pp \to pp \eta$. Our focus is on di-electrons from Dalitz decays of…
We calculate the dilepton emission rate from a fireball created in an ultra-relativistic heavy-ion collision. For the partonic phase, we complement the perturbative results by a phenomenological approach based on lattice QCD results,…
Dilepton production in In+In collisions at 158 AGeV is studied within the microscopic Parton-Hadron-Strings Dynamics (PHSD) transport approach, which is based on a dynamical quasiparticle model (DQPM) matched to reproduce lattice QCD…
First results of the differential cross section in dp elastic scattering at 1.25 GeV/u measured with the HADES over a large angular range are reported. The obtained data corresponds to large transverse momenta, where a high sensitivity to…