Entanglement Signatures of Kinetic-Mixing Portals in Dark Monopole Scattering
We examine the interaction between the Standard Model (SM) fermions and the topological dark magnetic monopoles mediated via a kinetic-mixing portal to investigate the generation of quantum entanglement in particle-portal scattering. While the conventional phenomenology only takes into account total cross-sections, decay widths, and missing-energy signatures, we employ an information-theoretic approach to explain the scattering event. We quantify the quantum correlations transported over the portal boundary by calculating the Von Neumann entropy ($S_{\text{ent}}$) and the subsystem purity deterioration ($γ< 1$) analytically. Our results demonstrate that the non-perturbative core form factor of the dark monopole controls its high-energy momentum transfer and that the Von Neumann entropy increases quadratically with the topological magnetic charge ($g_m^2$) and the kinetic-mixing parameter ($ε^2$). This paradigm provides an information-theoretic "microscope" to restrict portal parameter spaces and explore underlying topological structures without using traditional energy signatures by establishing quantum decoherence and purity loss as new, complementary observables.