Comparison of proton-proton bremsstrahlung data at 42 and 156 MeV with soft photon calculations

Proton-proton bremsstrahlung in principle provides information about the off-shell nucleon-nucleon force, but first the dominant on-shell contribution must be understood. Comparisons of purely on-shell soft photon calculations with 200 and 730 MeV data have already been made. In this paper similar comparisons are made for the remaining two modern experiments, those at 42 and at 156 MeV. For 42 MeV soft photon and standard potential model calculations differ by amounts comparable to, or somewhat larger than, the errors in the data which tend to fall in between the theoretical curves, which thus fit the data equally well. For the 156 MeV data the soft photon results are a slight improvement over potential models, but neither fit the data very well