Neutron-Proton Bremsstrahlung Compared to Experiment at 225 MeV

Neutron-proton bremsstrahlung ($np\gamma$) with out-of-plane contributions, relativistic spin effects, charge form-factor contributions, and meson-exchange effects included to order K in the photon momentum [1] are calculated with various modern nucleon-nucleon potentials to compare to experimental results at 225 MeV obtained by J. Matthews et al.[2] at LANCE. The data include various coplanar nucleon exit angles. These are the first experimental ($np\gamma$) data to explicitly measure the photon angular distribution. Finite-size detector effects are determined with the out-of-plane calculations. \newline \newline [1] V. R. Brown and J. Franklin, Phys. Rev. C {\bf 8}, 1706 (1973). \newline [2] J. Matthews and T. Akdogan, private communication.