相关论文: Dilepton production from p-p to Ca-Ca at the Beval…
The dilepton production in elementary ${pp\to e^{+}e^{-}X}$ reactions at BEVALAC energies $T_{lab}=1\div 5$ GeV is investigated. The calculations include direct ${e^{+}e^{-}}$ decays of the vector mesons $\rho ^{0}$, $\omega $, and $\phi $,…
We have performed a detailed study of dilepton production from pp collisions including the subthreshold $\rho$ production via baryonic resonances (N(1520), N(1700)) in addition to the conventional dilepton sources as $\pi^0, \eta, \omega$…
We present a dynamical study of $e^+e^-$ production in C + C and Ca + Ca collisions at BEVALAC/SIS energies on the basis of the covariant transport approach HSD employing momentum-dependent $\rho$-meson spectral functions that include the…
We study dilepton production from pp, pd and p Be collisions from 1 - 5 GeV including the $\pi^0$, $\eta$, $\omega$ and $\Delta$ Dalitz decays, direct decays of vector mesons ($\rho$, $\omega$) as well as subthreshold $\rho$ production via…
Dilepton production in nucleus-nucleus collisions at 1-2 A GeV as well as in elementary pp and pd reactions is studied within the microscopic HSD transport approach which includes the off-shell dynamics of vector mesons explicitly. The…
Dilepton production has been measured with HADES, the "High Acceptance DiElectron Spectrometer". In pp collisions at 2.2GeV kinetic beam energy, exclusive eta production and the Dalitz decay eta -> gamma e+e- has been reconstructed. The…
A full calculation of lepton-pair angular characteristics is carried out for $e^+e^-$ pairs created in $p + Be$ and $Ca + Ca$ collisions from 1.0 to 2.1 GeV/A. It is demonstrated that the dilepton decay anisotropy depends sensitively on the…
Dielectron mass spectra are examined for various nuclear reactions recently measured by the DLS collaboration. A detailed description is given of all dilepton channels included in the transport model UrQMD 1.0, i.e. Dalitz decays of…
Preliminary estimates suggest that excess dimuon production with invariant mass in the range 1.5 -- 2.5 GeV in nucleus-nucleus collisions can be explained on the basis of $\eta_c$ production. This appears to be consistent with all the…
We study dilepton production in proton-proton, Cu+Cu as well as in Au+Au collisions at the center-of-mass energy 200 GeV per participating nucleon pair within an extended statistical hadronization model. In extension to earlier studies we…
The inclusive reactions $pp \rightarrow e^+ e^- X$ and $np \rightarrow e^+ e^- X$ at the laboratory kinetic energy of 1.25 GeV are investigated in a model of dominance of nucleon and $\Delta$ resonances. Experimental data for these…
Dilepton production in intermediate energy nucleus-nucleus collisions as well as in elementary proton-proton reactions is analysed within the UrQMD transport model. For C+C collisions at 1 AGeV and 2 AGeV the resulting invariant mass…
HADES is the only operating dielectron spectrometer in the energy regime 1-2 AGeV. The physics program aims at a systematic investigation of dielectron production in heavy ion as well as elementary and pion-induced reactions. This…
We study the bremsstrahlung of virtual omega mesons due to the collective deceleration of nuclei at the initial stage of an ultrarelativistic heavy-ion collision. It is shown that electromagnetic decays of these mesons may give an important…
Dileptons represent a unique probe for nuclear matter under extreme conditions reached in heavy-ion collisions. They allow to study meson properties, like mass and decay width, at various density and temperature regimes. Present days models…
The emission of e+e- pairs from C+C collisions at an incident energy of 1 GeV per nucleon has been investigated. The measured production probabilities, spanning from the pi0-Dalitz to the rho/omega! invariant-mass region, display a strong…
In a recent work from the ALICE collaboration an excess of relatively soft dilepton pairs was reported in p+p collisions at $13$ TeV. In the report no satisfactory explanation was found via standard bremsstrahlung computations. In this…
Inclusive production of e+e--pairs in pp and dp collisions at a kinetic beam energy of 1.25 GeV/u has been studied with the HADES spectrometer. In the latter case, the main goal was to obtain data on pair emission in quasi-free np…
Dilepton production in proton- and nucleus-induced reactions is studied in relativistic transport model using initial conditions determined by the string dynamics from RQMD. It is found that both the CERES and HELIOS-3 data for dilepton…
We present a unified description of the vector meson and dilepton production in elementary and in heavy ion reactions. The production of vector mesons ($\rho,\omega$) is described via the excitation of nuclear resonances ($R$). The…