From gamma ray line signals of dark matter to the LHC

TL;DR

This paper investigates how gamma-ray signals from dark matter annihilation relate to potential LHC signatures within a specific secluded dark matter model involving a scalar mediator, aiming to connect astrophysical observations with collider experiments.

Contribution

It introduces a model where a scalar field mediates dark matter interactions, enhancing gamma-ray signals and predicting observable LHC signatures, bridging astrophysics and collider phenomenology.

Findings

Enhanced gamma-ray line signals without large couplings

Potential LHC signatures from scalar ta production

Modified Higgs decay rates to ta ta and ta Z

Abstract

We explore the relationship between astrophysical gamma-ray signals and LHC signatures for a class of phenomenologically successful secluded dark matter models, motivated by recent evidence for a ~130 GeV gamma-ray line. We consider in detail scenarios in which interactions between the dark sector and the standard model are mediated by a vev-less scalar field \phi, transforming as an N-plet (N > 3) under SU(2)_L. Since some of the component fields of \phi carry large electric charges, loop induced dark matter annihilation to \gamma \gamma and \gamma Z can be enhanced without the need for non-perturbatively large couplings, and without overproduction of continuum gamma-rays from other final states. We discuss prospects for other experimental tests, including dark matter-nucleon scattering and production of \phi at the LHC, where future searches for anomalous charged tracks may be sensitive. The first LHC hints could come from the Higgs sector, where loop corrections involving \phi lead to significantly modified h to \gamma \gamma and h to \gamma Z branching ratios.