Theory HEP Seminar

Photon Masses in the Landscape and Dark Photon Dark Matter

Matthew Reece

Harvard

In effective field theory, spin-2 particles can have two kinds of masses, Stuckelberg masses or masses arising from the Higgs mechanism. In the first half of the talk I will clarify the distinction between the two types and argue that a version of the Weak Gravity Conjecture places strong constraints on Stuckelberg masses. I will comment on implications for the mass of the Standard Model photon and for dark photons. In the second half of the talk I will discuss a new cosmological mechanism for populating dark photon dark matter, which operates by storing energy in an axion field that efficiently converts into dark photons.