Measurements of the virtual bremsstrahlung in the p+p and p+d systems

Virtual bremsstrahlung yields measured in (p) over bar+p-->p+p+e(+)+e(-) and (p) over bar+d-->He-3+e(+)+e(-) are presented. The experiments were performed with a 190 MeV polarized proton beam obtained from the cyclotron AGOR at KVI in Groningen. Differential cross sections, response functions and analyzing powers were obtained for both reactions in exclusive measurements in which all outgoing particles were measured in a coincidence setup between SALAD and TAPS. The data are compared with gauge-invariant calculations using a NN T-matrix fitted to elastic phase-shifts. For pp-->ppe(+) e(-) a reasonable agreement is found for all measured virtual-photon invariant masses, M-gamma > 15 MeV/c(2) up to 80 MeV/c(2). For the pd-->He-3 e(+)e(-) angular distributions, the calculations underestimate the data for theta(CM) >100 degrees similar to what is found in the real-photon capture reaction.