Gillian Kopp, Pappalardo Fellow

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Area of Physics

Experimental Particle Physics

Research Interests

The Large Hadron Collider (LHC) at CERN collides protons every 25 ns, and large underground detectors record the results of these collisions to study the interactions of elementary particles. Gillian Kopp develops novel detection and analysis methods to increase sensitivity to rare particle physics processes and address outstanding questions in fundamental physics such as the nature of dark matter. She works on the Compact Muon Solenoid (CMS) experiment, using this precision detector to probe physics beyond the known Standard Model. 

Gillian’s work increases the sensitivity of collider experiments to physics beyond the Standard Model by implementing hardware-level delayed and displaced jet trigger algorithms to identify long-lived particle decays. These triggers access a new region of phase space, enabling an extended physics search with the data collected by CMS over the past few years. This also led to new time alignment methods for the hadron calorimeter, improving detector performance and providing more accurate timing measurements. She centers detector hardware in her work, currently serving as the co-convenor of the CMS hadron calorimeter (HCAL) detector performance group. Gillian is now pursuing a comprehensive dark sector research program, using precision timing information to identify rare events, developing unique long-lived particle analysis approaches, and exploring detector development for smaller experiments to complement the collider approach.

Biographical Sketch

Gillian grew up in Boulder, Colorado. She received her BS in physics from Caltech in 2018, and her Ph.D. in experimental particle physics at Princeton University in 2024, working on the CMS experiment at CERN. At Caltech, she joined Prof. Maria Spiropulu’s group, working on precision timing detector development. During her dissertation work, she designed and implemented novel hardware-level algorithms to identify theorized long-lived particles with Prof. Chris Tully.

Gillian greatly enjoys spending time in the outdoors, particularly through hiking, skiing, and climbing.

Selected Publications

• CMS Collaboration. Long-Lived Particle Triggers at CMS: Strategy and Performance during early LHC Run 3. CMS PAPER EXO-23-016 (in preparation), October 2024.
• Gillian Baron Kopp on behalf of the CMS Collaboration. Long-lived Particle Triggering with the CMS Hadron Calorimeter. Proceedings of Science, September 2024. https://cds.cern.ch/record/2911737?ln=en
• Gillian Kopp, Chris Tully, Kiley Kennedy, et.al. A Novel Timing Trigger with the CMS Hadron Calorimeter. CMS DN-2023/022, 31 October 2023. https://cds.cern.ch/record/2891496?ln=en