Spin observables inppbremsstrahlung and off-shell effects of theNNinteraction

The spin-correlation coefficients in pp bremsstrahlung are calculated in order to investigate their sensitivity to off-shell effects of the nucleon-nucleon interaction. Overall, in the coplanar geometry, we find that these coefficients are very sensitive to off-shell effects. This holds even at proton scattering angles as large as ${\mathrm{\theta }}_1$=${\mathrm{\theta }}_2$=20°, where the analyzing power is weakly sensitive to these effects, the measurements are less difficult, and the interpretation of the data is more transparent than at smaller proton scattering angles.