Final-State Effects in Atomic Processes: Photodetachment

A formalism which corrects Born-approximation amplitudes for final-state effects in atomic scattering and detachment processes is developed from use of Jost function enhancement factors. The method leads to soluble integral equations of the Omnès type. Application is made to the photodetachment of negative oxygen ions ($\gamma +O^{-}\to O+e^{-}$), yielding an improved fit to recent experimental data. The theory is compared with earlier work of Klein and Brueckner.