Dark moments for the Standard Model?

A bstract If dark matter (DM) interacts with the Standard Model (SM) via kinetic mixing (KM) portal, it necessitates existence of portal (PM) particles which carry both and SM quantum numbers that will appear in vacuum polarization-like loop graphs. In addition to familiar ∼ eϵQ strength, QED-like interaction for photon (DP), some setups different graphs these PM states can also induce other coupling structures fermions may come dominate at least regions parameter space take form ‘dark’ moments, e.g., magnetic dipole-type interactions IR, associated a large mass scale, Λ. this paper, motivated by simple toy model, we perform phenomenological investigation possible loop-induced dipole moment fermions, particular, electron. We show level such scenario not only be made compatible existing experimental constraints significant range correlated values Λ U(1) D gauge coupling, g , but lead quantitatively signatures once DP is discovered. setup, assuming complex scalar DM satisfy CMB constraints, where decays invisibly are found somewhat preferred if limits from direct searches LHC our model setup all taken seriously. High precision for, or measurements of, e + − → γ process Belle II shown provide strongest future on scenario.