Description:

Title: Dark Matter, On Demand

Speaker: Kristian Hahn, Northwestern University, Department of Physics & Astronomy

Abstract: 

The matter content of the universe is thought to be dominated by a substance of which little is known. A broad field of terrestrial and space-borne experiments have sought to establish the particle nature of this "Dark Matter" by detecting its interactions with familiar standard model particles. The very same interactions are presently probed by experiments at the CERN Large Hadron Collider (LHC). The LHC offers the potential to directly produce and study Dark Matter particles in the lab via their couplings to quarks.

In this talk I will describe the evolution and status of Dark Matter searches with the Compact Muon Solenoid (CMS) experiment at the LHC. We will see that in many cases CMS provides sensitivity to Dark Matter interactions that nicely complements that of direct and indirect detection experiments. There are good reasons to suspect that Dark Matter should interact with the standard model through a new spin-0 mediator particle. In this case, Dark Matter will preferentially couple to the heaviest quarks -- top and bottom. I will highlight CMS searches for Dark Matter produced together with top and bottom quark pairs, a production mode that gives rise to rich detector signatures and unique sensitivity to low-mass scalar and pseudoscalar mediators.

The ultimate sensitivity to Dark Matter production at the LHC will be achieved through a large increase in beam luminosity beginning in 2026. The physics environment of the "high-luminosity" LHC will be incredibly challenging because of the corresponding increase in the number of soft interactions occurring in each beam crossing. The key enabler of CMS physics goals in this period will be the ability to perform real-time charged particle tracking in the experiment's trigger system. I will review the R\&D that has shown this to be feasible, and I will discuss how the experiment is proceeding toward the design and construction of novel real-time tracking trigger electronics.

Host: Schmitt

Speaker Schedule

Keywords: Physics, Astronomy, colloquium