A Mass for the Dual Photon

We explore a novel IR phase of electromagnetism and place constraints on it. The usual IR modification of electromagnetism, the Higgs phase, involves adding a photon mass for the gauge field $A_\mu$, which screens electric fields and confines magnetic fields. We explore the confined phase resulting from adding a mass term for the dual photon, which screens magnetic fields and confines electric fields. We study the theory of a dual photon mass and argue that it is a consistent effective field theory. We then elucidate the phenomenological consequences of such a mass term and derive constraints on it. As the current constraints come with large uncertainties, we also propose a few new searches for a dual photon mass term.