Confronting the Fermi Line with LHC data: an Effective Theory of Dark Matter Interaction with Photons

Abstract

We describe an effective theory of interaction between pairs of dark matter particles and pairs of photons. Such an interaction could accomodate $\chi \bar{\chi }\to \gamma \gamma$ processes which might be the cause of the observed feature in the FermiLAT spectrum, as well as ${\gamma }^{\ast }/Z\to \gamma \chi \bar{\chi }$ processes, which would predict excesses at the LHC in the $\gamma +\text{missET}$ final-state. We reinterpret an ATLAS $\gamma +\text{missET}$ analysis and the observed Fermi feature in the parameter space of our new effective theory to assess their consistency.