Light and Darkness: consistently coupling dark matter to photons via effective operators

Understand

We revise the treatment of fermionic dark matter interacting with photons via dimension-5 and -6 effective operators.

• We show how the application of the effective operators beyond their validity introduces unphysical, gauge violating effects that are relevant for current experimental searches.
• Restoring gauge invariance by coupling dark matter to the hypercharge gauge field has implications for the parameter space above and below the electroweak scale.
• We review the phenomenology of these hypercharge form factors at the LHC as well as for direct and indirect detection experiments.