Constraining the Higgs-Dilaton with LHC and Dark Matter Searches

TL;DR

This paper investigates a dilaton-Higgs mixing scenario where the dilaton acts as a portal to dark matter, analyzing collider and dark matter constraints to identify viable parameter space and future detection prospects.

Contribution

It introduces a model linking the dilaton to dark matter via Higgs mixing and constrains it using current collider and dark matter search data.

Findings

Decoupling limit with high CFT scale is favored by data.

Dark matter likely has a mass above 1 TeV.

Future experiments could detect dilaton-mediated dark matter.

Abstract

We study a scenario in which the dilaton, a pseudo-Goldstone boson of the spontaneous breaking of conformal symmetry, provides a portal between dark matter and the visible sector. We consider the low-energy description of the theory in which the dilaton mixes with the Standard Model Higgs boson, thereby predicting a second scalar at or above the weak scale. We derive the collider and dark matter constraints on the corresponding parameter space and find that existing experimental data point towards the decoupling limit in which the CFT scale is well above the electroweak scale. Moreover, the thermal production of dark matter implies its mass is likely above the TeV scale. Upcoming direct detection experiments may allow for the discovery of the dilaton-mediated thermal dark matter while future collider studies will also be sensitive to the available parameter space.