Search for Inelastic Dark Matter with Soft Displaced Electrons in CMS Run 3

This talk presents a search for dark matter production in Large Hadron Collider (LHC) proton-proton collisions with the Compact Muon Solenoid (CMS) detector, targeting an Inelastic Dark Matter (IDM) model that explains the thermal-relic abundance while evading direct detection. The IDM model predicts at least two dark-sector states with a small mass splitting, accompanied by a dark photon that mixes kinetically with the Standard Model (SM) hypercharge. The heavier state (a Long Lived Particle (LLP)) decays into a pair of muons or electrons after traveling a finite distance. LLP signatures are advantageous because SM backgrounds are minimal, enabling the study of softer final-state particles—both motivating and challenging. The analysis focuses on events with soft, displaced electrons and missing transverse energy, using early Run 3 (2022–2023) data at a center-of-mass energy of 13.6 TeV. A key aspect of my present work is replicating the Run 2 analysis for Run 3 to ensure that reconstruction, detector performance, and analysis procedures are fully understood, confirming the absence of unexpected issues.