Proton-proton Bremsstrahlung

We calcuate differential scattering cross sections for the proton-proton bremsstrahlung (p + p → p + p + γ) process. This reaction involves both the nuclear (strong) and electromagnetic interactions between the protons. We treat the electromagnetic interaction to first order in perturbation theory and we construct a modified one-boson-exchange (OBE) model to treat the nuclear interaction. We postulate a new meson to treat the S wave, which is usually omitted from OBE models. In order to enforce unitarity on the strong interaction matrix elements, we perform a partial wave analysis and unitarize the partial wave amplitudes by means of the K-matrix technique. We find that to obtain reasonable agreement with the experimental cross sections it is necessary to use pseudovector, as opposed to pseudoscalar, pion-nucleon coupling