Collider probes of singlet fermionic dark matter scenarios for the Fermi gamma-ray excess

Abstract

We investigate the collider signatures of three benchmark points in the singlet fermionic dark matter model motivated by the Fermi gamma-ray excess at the Galactic center. The benchmark points are classified according to the final state of the main dark annihilation process: a pair of b quarks, Higgs bosons and new scalar bosons. Since the dark sector in the model communicates with the visible sector through a mixing between the new scalar and the Higgs boson, collider observables related to the measurements of Higgs boson properties and searches for the new scalar boson are essential to probe the benchmark scenarios at colliders. In this paper, we consider four collider observables: (1) Higgs signal strength (essentially hZZ coupling), (2) triple Higgs coupling, (3) exotic Higgs decay, and (4) direct production of the new scalar particle. We find that the benchmark points have distinctive collider signatures that can be well tested by the interplay of future lepton and hadron colliders.