Related papers: Dilepton production and off-shell transport dynami…
We address the dilepton production from the parton interactions in the early stage of relativistic heavy-ion collisions within the parton-hadron-string dynamics (PHSD) off-shell transport approach. The description of partons in PHSD is…
According to the dynamical quasiparticle model (DQPM) -- matched to reproduce lattice QCD results in thermodynamic limit, -- the constituents of the strongly interacting quark-gluon plasma (sQGP) are massive and off-shell quasi-particles…
The invariant-mass spectrum of $e^+ e^-$ pairs produced in $^{12}$C+$^{12}$C collisions at an incident energy of 2 GeV per nucleon has been measured for the first time. The measured pair production probabilities span over five orders of…
We calculate elementary proton-proton and neutron-proton bremsstrahlung and their contribution to the $e^+e^-$ invariant mass distribution. At 4.9 GeV, the proton-proton contribution is larger than neutron-proton, but it is small compared…
The HADES spectrometer installed at GSI Darmstadt is devoted to study the production of di-electron pairs from proton, pion and nucleus induced reactions at 1-2 AGeV. In pp collisions at 2.2 GeV we have focused mainly on exclusive…
According to the dynamical quasiparticle model (DQPM) - matched to reproduce lattice QCD results in thermodynamic limit, - the constituents of the strongly interacting quark-gluon plasma (sQGP) are massive and off-shell quasi-particles…
In this contribution we report $e^{+}e^{-}$ spectra with various invariant mass and p$_{T}$ differentials in Au$+$Au collisions at $\sqrt{s_{NN}}$=200 GeV and U$+$U collisions at $\sqrt{s_{NN}}$=193 GeV. The structure of the t ($t\approx…
The production of $K^+$ mesons in proton-nucleus collisions from 1.0 to 2.3 GeV is analyzed with respect to one-step nucleon-nucleon $(NN\to N Y K^+$) and two-step $\Delta$-nucleon $(\Delta N \to K^+ Y N$) or pion-nucleon $(\pi N \to K^+ Y…
We investigate dilepton production in transport-based approaches and show that the baryon couplings of the $\rho$ meson represent the most important ingredient for understanding the measured dilepton spectra. At low energies (of a few GeV),…
The enhancement in the dilepton spectrum observed in heavy-ion collisions for invariant electron-positron masses in the range 0.15 GeV/c$^2 < M_{e^+e^-} <$ 0.6 GeV/c$^2$ has recently been traced back to a corresponding enhancement in $pn$…
Data on inclusive dielectron production are presented for the reaction p+p at 2.2 GeV measured with the High Acceptance DiElectron Spectrometer (HADES). Our results supplement data obtained earlier in this bombarding energy regime by DLS…
$\mathbf{Purpose}$: Incoherent processes in production of lepton pairs in the scattering of protons off nuclei are investigated. $\mathbf{Methods}$: New quantum mechanical model is constructed which uses generalization of the nuclear model…
Dark photons, the hypothetical gauge bosons associated with an additional $U(1)^{\prime}$ symmetry, can couple to Standard Model particles through a small kinetic mixing parameter $\varepsilon$ with the ordinary photon. This mechanism…
We calculate dilepton production for the reactions $\pi^-$C and $\pi^-$Pb at 1.3 GeV within a semi-classical BUU transport model and compare our results to a previously published calculation. We show that a modified treatment of the…
We report on the investigation of $\Delta$(1232) production and decay in proton-proton collisions at a kinetic energy of 1.25 GeV measured with HADES. Exclusive dilepton decay channels $ppe^{+}e^{-}$ and $ppe^{+}e^{-}\gamma$ have been…
We study the production of $c \bar{c}$ pairs and dimuons from hard collisions in nuclear reactions within the covariant transport approach HSD, which describes successfully both hadronic and electromagnetic observables from p+A and A+A…
Due to their weak coupling to the strongly interacting matter produced in relativistic heavy-ion collisions, dileptons serve as a sensitive probe of the initial geometry of the colliding nuclei. In this study, we investigate the influence…
Starting from a realistic one--boson--exchange--model fitted to the amplitudes of elastic nucleon--nucleon scattering and the process $NN\rightarrow N\Delta$ we perform a fully relativistic and gauge invariant calculation for the dilepton…
Within an effective Lagrangian model, we present calculations for cross sections of the dilepton production in proton-proton and proton-neutron collisions at laboratory kinetic energies in 1-5 GeV range. Production amplitudes include…
Invariant mass spectra of di-electrons stemming from bremsstrahlung processes are calculated in a covariant diagrammatical approach for the exclusive reaction D p \to p_{\rm sp} n p e^+ e^- with detection of a forward spectator proton,…