FLArE up dark sectors with EM form factors at the LHC forward physics facility

Despite being mostly secluded, dark sector particles may feebly interact with photons via a small mass-dimension 4 millicharge, 5 magnetic and electric dipole moment, or 6 anapole moment charge radius. If sufficiently light, the LHC produce an intense collimated beam of these in far forward direction. We study prospects searching for such electromagnetic form factors their electron scattering signature Forward Liquid Argon Experiment (FLArE) detector at Physics Facility (FPF). find that FLArE can provide new probes sub-GeV moments strong sensitivities millicharged 100 MeV to GeV region. This complements other search strategies using scintillation signatures matter direct detection allows probing strongly interacting motivated by EDGES anomaly. Along FORMOSA detector, this leads very diverse leading experimental program FPF.