Coulomb Effects in Momentum-Space Femtoscopy: A Case Study of the $\bar{K}\mathrm{\Omega }$ System

We present a momentum-space framework for the consistent treatment of Coulomb interactions in femtoscopic correlation functions based on a modified Vincent–Phatak method that is more amenable to numerical implementation. The formalism provides a practical approach to incorporating Coulomb effects at the short distances relevant for femtoscopy within the Lippmann–Schwinger equation, while preserving a unified treatment of the strong interaction. As an application, we study the $S=-4$ pseudoscalar–baryon decuplet interaction in the $\bar{K}\mathrm{\Omega }$ system and present predictions for the singly and doubly negatively charged channels, ${\bar{K}}^0{\mathrm{\Omega }}^{-}$ and $K^{-}{\mathrm{\Omega }}^{-}$. As an additional validation of the formalism, we have also applied it to the well-studied $pp$ system. We further assess the limitations of the asymptotic wave-function approximation and quantify corrections accounting for the short-distance structure of the interaction potential. We introduce a phenomenological parameter that effectively absorbs contributions from both the finite source size and the off-shell structure of the interaction, the latter being one of the main obstacles to extracting detailed information on hadron–hadron interactions from femtoscopic measurements in a model-independent way.