Bremsstrahlung Cross Section with Polarized Beams for Luminosity Determination at the EIC

Abstract

The bremsstrahlung cross section is calculated at leading order for polarized beams of electrons and ions, which is needed for luminosity measurements at the upcoming Electron Ion Collider (EIC). Analytic expressions, differential in the emitted photon energy and polar angle, are derived. The component of the cross section which depends on the beam polarizations is found to be highly suppressed with respect to the unpolarized Bethe-Heitler component, owing to the low $q^2$ that characterizes the bremsstrahlung process.