  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
collisions. To select this particular reaction channel the HADES experimental
setup was extended with a Forward Wall hodoscope, which allowed to register
spectator protons. Here, the measured invariant mass distributions demonstrate
a strong enhancement of the pair yield for M > 140 MeV/c2 in comparison to pp
data.
