Speaker
Description
Recent Fermi-LAT observations of dwarf spheroidal galaxies in the Milky Way have placed strong
limits on the gamma-ray flux from dark matter annihilation. In order to produce the strongest limit
on the dark matter annihilation cross-section, the observations of each dwarf galaxy have typically
been “stacked” in a joint-likelihood analysis, utilizing optical observations to constrain the dark
matter density profile in each dwarf. These limits have typically been computed only for singular
annihilation final states, such as
b
̄
b
or
τ
+
τ
−
. In this paper, we generalize this approach by producing
an independent joint-likelihood analysis to set constraints on models where the dark matter particle
annihilates to multiple final state fermions. We interpret these results in the context of the most
popular simplified models, including those with s- and t-channel dark matter annihilation through
scalar and vector mediators. We present our results as constraints on the minimum dark matter
mass and the mediator sector parameters. Additionally, we compare our simplified model results to
those of Effective Field Theory contact interactions in the high-mass limit.
