Dark Neutrino Moments From Light Loops

Active and sterile neutrinos may acquire "dark moments" via one-loop diagrams with a massless dark photon and new light particles in the loop. Due to the kinetic mixing between the dark photon and the Standard Model photon, neutrinos would obtain effective electromagnetic moments. This mechanism allows for enhanced electromagnetic moments that can evade constraints on particles directly charged under electromagnetism. We show that in a wide region of parameter space, the model features testable predictions for the anapole and magnetic moment of active and sterile neutrinos with dark matter direct detection experiments sensitive to the solar neutrino flux.