Di-photon excess illuminates Dark Matter

TL;DR

This paper introduces a simplified dark matter model with a scalar mediator to explain the ATLAS and CMS di-photon excess, predicting a 300 GeV dark matter particle detectable in future collider and direct detection experiments.

Contribution

It presents a novel simplified dark matter model linking the di-photon excess to dark matter properties and makes testable predictions for collider and astrophysical experiments.

Findings

Model accommodates large resonance width with dark matter decays

Predicts a 300 GeV dark matter particle detectable at LHC Run II

Future direct detection experiments will probe this scenario

Abstract

We propose a simplified model of dark matter with a scalar mediator to accommodate the di-photon excess recently observed by the ATLAS and CMS collaborations. Decays of the resonance into dark matter can easily account for a relatively large width of the scalar resonance, while the magnitude of the total width combined with the constraint on dark matter relic density lead to sharp predictions on the parameters of the Dark Sector. Under the assumption of a rather large width, the model predicts a signal consistent with ~300 GeV dark matter particle in channels with large missing energy. This prediction is not yet severely bounded by LHC Run I searches and will be accessible at the LHC Run II in the jet plus missing energy channel with more luminosity. Our analysis also considers astrophysical constraints, pointing out that future direct detection experiments will be sensitive to this scenario.