Noncoplanarity in proton-proton bremsstrahlung

Abstract

Using the soft-photon approximation, we address the issue of the importance of noncoplanarity effects in proton-proton bremsstrahlung. We investigate the noncoplanar cross section as a function of the noncoplanarity angle $\overline{\ensuremath{\varphi}}$ for the entire range of the photon polar angle ${\ensuremath{\psi}}_{\ensuremath{\gamma}}.$ The $\overline{\ensuremath{\varphi}}$ dependence is shown to provide a significant variation in the cross section, for a given ${\ensuremath{\psi}}_{\ensuremath{\gamma}}.$ Thus, there can be some uncertainty in determining experimental coplanar cross sections. To avoid the phase-space singularities of spherical geometry, we utilize the Harvard noncoplanar geometry. A detailed explication of the Harvard geometry is provided. Comparison of our calculations with experimental data is included.