Proton-proton bremsstrahlung at the threshold region of the pion production Original Research Article

Squared matrix elements for the correlation between the nucleon-pole and pion-loop amplitudes are calculated in order to investigate an observed cusp-like structure in proton-proton bremsstrahlung at the threshold region of the pion production. The results so far including only one-pion-exchange mechanism between two protons shows little evidence for such a cusp-like structure at the pion threshold.