Broadening Dark Matter Searches at the Large Hadron Collider

Krovi, Venkat Sai Anirudh

doi:https://doi.org/10.21985/n2-r6dd-r112

Work

Broadening Dark Matter Searches at the Large Hadron Collider

Public

Download PDF

Download All Files (.zip)

We broaden the scope of existing dark matter searches at the Large Hadron Collider (LHC) by considering phenomena such as bound state formation and by utilizing simple extensions of well-studied models in the literature. First, we consider the Mono-X studies at the LHC, where the production of dark matter occurs in association with a Standard Model (SM) particle. The simplest benchmark model used in these studies introduces a massive spin-1 mediator, the Z' boson, between the dark matter and the SM. Limits derived from mono-X channels are most effective when the mediator can decay into two on-shell dark matter particles. We extend the experimental reach into the complementary region, where the Z' mediator is much lighter than the dark matter. In this scenario, the Z' mediates an effective long-range force between the dark matter, thereby facilitating the formation of darkonium bound states. Considering multijet final states that occur as a result of the decay of the bound state, we reinterpret existing searches to constrain the simple Z' benchmark beyond the region probed by mono-X searches. Second, we introduce a light dark photon to the minimal Higgs portal model by coupling the Higgs boson to 'dark QED' containing fermionic dark matter. This addition gives rise to rich collider phenomenology. There are two prominent features in such a simple extension -- the Higgs boson could have decays into the long-lived dark photon through the `mono-dark photon channel', or into multiple collimated leptons via a dark matter bound state, depending on the mixing parameter of the dark photon with the visible photon. We initiate new studies probing the parameter space of the model in both the energy and the lifetime frontiers at the LHC.

Creator