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

TL;DR

This paper explores collider signatures of specific singlet fermionic dark matter models designed to explain the Fermi gamma-ray excess, predicting detectable signals at future colliders like the ILC and HL-LHC.

Contribution

It provides detailed collider predictions for three benchmark dark matter scenarios linked to the Fermi gamma-ray excess, highlighting testable signals at upcoming experiments.

Findings

Detectable deviations in Higgs signal strength and triple Higgs coupling.

Exotic Higgs decays and new scalar production are observable.

Future colliders can test these dark matter scenarios effectively.

Abstract

We investigate the collider signatures of the three benchmark points in the singlet fermionic dark matter model. The benchmark points, which were introduced previously to explain the Fermi gamma-ray excess by dark matter (DM) pair annihilation at the Galactic center, have definite predictions for future collider experiments such as the International Linear Collider and the High-Luminosity LHC. 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 a new scalar particle. The benchmark points are classified by the final states of the DM annihilation process: a pair of $b$ quarks, SM-like Higgs bosons, and new scalar particles. Each benchmark scenario has detectable new physics signals for the above collider observables that can be well tested in the future lepton and hadron colliders.