Abstract:
The LHC Run 2 data set, with its unprecedented energy and luminosity, has provided an invaluable opportunity to explore the existence of SUSY. In particular, the production of electroweakinos (neutralinos and charginos) and sleptons can be better explored only with the full Run 2 data set to account for the low cross sections and experimentally challenging final states that require development of new analysis techniques. Expanding the typical SUSY searches is crucial to target challenging parts of the SUSY parameter space, such as compressed mass spectra scenarios, where SUSY could still be hiding. Furthermore, combinations of individual searches provide unique opportunities to extend existing constraints on signal models that are otherwise out of reach.
After a short introduction to the topic and the models used to study the compressed mass spectra scenarios by both ATLAS and CMS Collaborations, we present the latest results of such searches. We pay special attention to the combination of electroweak SUSY searches, and the parts of the parameter space such combinations have covered. These legacy results will constitute the final word on EWK SUSY using Run 2 data and will provide the strongest constraints for years to come. Additionally, we discuss the blind spots and where future efforts could potentially be directed.
Jaana Heikkilä is an experimental physicist at the CMS experiment. She earned her PhD in 2019 from the University of Helsinki and is currently a post-doc at the University of Zürich. In the near future, she will begin her CERN Fellowship. Over her decade-long career, she has focused on measuring the properties of the Standard Model Higgs boson and searching for new physics predicted by Supersymmetry. For her PhD thesis, she performed a search for additional Higgs bosons decaying into high-pT final state objects (A→Zh→ℓℓ𝛕𝛕), whereas during her postdoc she has taken part to search for electroweak production of neutralinos, charginos, and sleptons in compressed mass spectra scenarios. Recently, she led the statistical combination of six searches performed by the CMS Collaboration using the LHC Run 2 data set, targeting the electroweak production of the aforementioned supersymmetric particles. Additionally, she actively contributes to the development and operation of the L1 Trigger.
Jeff Shahinian is a postdoctoral researcher at the University of Pennsylvania and a member of the ATLAS Collaboration whose research focuses on searches for the Electroweak production of Supersymmetric particles. Prior to graduate school, he spent his first year at CERN during LS1 performing technical work on the calibration system and front-end electronics of the ATLAS detector’s hadronic calorimeter. Following this experience, Jeff attended the University of California, Santa Cruz where he received his PhD in 2020 with his dissertation presenting searches for the direct production of electroweakinos and sleptons within compressed mass spectra using the full Run 2 ATLAS dataset. Since joining the University of Pennsylvania, he has continued leading these searches for compressed SUSY and has served as co-convener of the Electroweak SUSY subgroup in ATLAS since October, 2021. Beyond physics analysis, Jeff is deeply involved in operating the data acquisition system of the Transition Radiation Tracker.