Michelle Contreras Cossio, UT-Austin

"Searching for Long Lived Particles using the Liquid Argon Electromagnetic Calorimeter from the ATLAS Detector"

Abstract: The benchmark for progress in particle physics revolves around the identification of new particles. Following the landmark discovery of the Higgs boson in 2012 by the ATLAS and CMS experiments at the LHC, the final puzzle piece for completing the Standard Model fell into place. Nonetheless, the Standard Model alone falls short in explaining certain phenomena, such as dark matter, particle-antiparticle asymmetry, and other enigmas. This suggests the need for new theories beyond the Standard Model.

For decades, the search for novel particles concentrated on heavy particles with short lifetimes. However, there has been a notable shift in recent times, with a focus on Long-Lived Particles. These particles are present in several beyond-the-Standard-Model theories and have reshaped the paradigm for particle exploration across a wide spectrum of new and existing experiments, including the ATLAS detector.

This talk presents an overview of the ongoing and forthcoming searches for signatures of Long-Lived Particles, making use of the high-precision spatial and timing capabilities of the ATLAS Liquid Argon electromagnetic calorimeter. Additionally, it highlights the current efforts by the UT ATLAS group to enhance the calorimeter readout electronics through the design and testing of the COLUTA analog-to-digital-converter.