Dilepton production in pp and CC collisions with HADES.

e⁺e⁻ production was studied using the High Acceptance DiElectron Spectrometer (HADES). In pp collisions at 2.2 GeV kinetic beam energy, the exclusive η production and the Dalitz decay η → νe⁺e⁻ have been reconstructed. The electromagnetic form factor of the latter decay was found to be in good agreement with the existing theoretical predictions. In addition, an inclusive e⁺e⁻ invariant-mass spectrum from the ¹²C + ¹²C reaction at 2 AGeV is presented and compared with a simplified thermal model. [ABSTRACT FROM AUTHOR]