Soft-photon analysis of nucleon-nucleon bremsstrahlung: Anomalous magnetic moment effects

Two soft-photon amplitudes, the Low amplitude and the two- u-two-t special amplitude, agree with one another in the case of npgamma but disagree significantly in the case of ppgamma. The two- u-two-t special amplitude describes well the available ppgamma cross section data. The relationship between the two amplitudes as well as the reason they agree and disagree is explored. Using these two soft-photon amplitudes plus a one-boson exchange amplitude, the contribution of the proton and neutron anomalous magnetic moments to ppgamma and npgamma has been investigated for projectile energies above 150 MeV and for laboratory scattering angles lying between 8degrees and 35degrees. The anomalous magnetic moment contribution was found to be significant in the ppgamma process but insignificant in the npgamma process. Additional aspects of the bremsstrahlung mechanism are discussed. Our findings play an important role in understanding the similarities and differences between the Low amplitude and the two-u-two-t special amplitude as well as why the two-u-two-t special amplitude calculation agrees well with the available ppgamma cross section data.