Speakers
Description
The High Acceptance DiElectron Spectrometer (HADES) is dedicated to the measurement of electromagnetic probes from heavy ion collisions and to study the in-medium behaviour of dileptons in the moderate temperature and high density regime of the QCD phase diagram. The spectral distributions of dileptons reveal the thermal properties of the medium. With the recent upgrade of the HADES RICH detector an unprecedented quality and signal-to-background ratio was achieved in the detection of these extremely rare probes.
In this talk we present preliminary results on the dielectron analysis of the HADES Ag+Ag data at a centre-of-mass energy of $\sqrt{s_{NN}} = 2.55 \, GeV$. The high statistics of the HADES data taking in combination with a strongly increased electron detection efficiency allow even for a signal in the $\Phi$-meson mass region. The obtained dielectron signal spectrum will be compared to simulated hadronic cocktail and nucleon-nucleon reference spectra clearly revealing a contribution from the medium.
