Galactic Center Gamma-ray Excess through a Dark Shower

TYPEJoint Particle Physics Seminar
Speaker:Dean Robinson
Affiliation:Berkeley & LBNL
Organizer:Yael Shadmi
Location:Lidow 620

The reported galactic center gamma-ray excess has a distribution and
rate suggestive of an origin in dark matter annihilations. However, the
conventional DM annihilation channels into standard model b quarks or
tau leptons are increasingly in tension with various experimental
constraints on antiproton and positron fluxes. I'll discuss a framework
that is free from such constraints. The key idea is that the mediators
between the dark matter and the SM are themselves part of a strongly
coupled sector: a hidden valley. DM annihilation produces a dark hadron
shower that in turn decays to photons, but without significant
associated emission of other SM matter. I'll also discuss an explicit
realization of this framework, its phenomenology, as well as pertinent
cosmological, astrophysical and collider bounds.