Overview: The Standard Model of Particle Physics (SM) has been incredibly successful, with all of its predictions validated by observations. The discovery of the Higgs boson (H) in 2012 by the ATLAS and CMS experiments at the Large Hadron Collider (LHC) was a triumph of the SM. Since its discovery, many measurements of the Higgs boson’s properties have been carried out, and so far all the results agree with the SM predictions within the uncertainties. However, to fully understand the recently discovered Higgs boson and the nature of electroweak symmetry breaking, it is important to establish whether the 125-GeV Higgs boson is the single Higgs boson of the SM or is it part of an extended scalar sector. The proposed research aims to search for additional Higgs bosons predicted in Type-I Two-Higgs-Doublet Models (2HDM), a class of theoretically well-motivated extensions of the SM. In this framework, the discovery of a heavier neutral Higgs boson would provide direct evidence of new physics, potentially addressing fundamental questions about the early universe and electroweak symmetry breaking.

Intellectual Merit: ATLAS is a general-purpose particle detector built cylindrically around the proton-proton collision point at the LHC. It measures the resulting particles from proton-proton collisions at the highest achievable energies in a laboratory. The LHC completed its first run (2010–2013), second run (2015–2018, Run2), and continues to take data in its third run (Run3). The combined Run2+Run3 data set is expected to amount to several hundred fb^-1 by the end of Run3. The proposed research will analyze this combined dataset to search for BSM Higgs bosons in the yet unexplored bbWW channel. This channel provides a rare opportunity to fully reconstruct both the signal and the dominant top-quark background, enabling enhanced discrimination between signal and background. To maximize sensitivity to the BSM Higgs signal, the Washington College ATLAS group will lead efforts to improve trigger efficiency for signal events, enhance event reconstruction through kinematic fitting techniques, and develop multivariate analysis frameworks informed by kinematic fits for signal and background classification. In the process, the project will also contribute to the calibration of b-jet triggers, benefiting a broad range of ATLAS analyses. This project will advance the physics program of ATLAS, and give us deeper insight into the nature of electroweak symmetry breaking and the possible existence of an extended Higgs sector.

Broader Impacts: The proposed initiative will establish a comprehensive research, education, and outreach program in particle physics at Washington College. This project will build a transformative undergraduate research program that trains students in advanced experimental techniques within the ATLAS Collaboration at CERN. Undergraduate students will engage directly in the analysis of LHC data, gaining experience in global, cutting-edge research collaborations. Through hands-on research, students will develop into competitive candidates for graduate study and leadership roles in the scientific workforce.
Beyond campus, the PI will lead outreach activities targeting high school students in rural communities on Maryland's Eastern Shore that have limited access to STEM resources and opportunities.
Programs such as hands-on particle physics labs using portable detectors, interactive Python-based data analysis workshops, and campus visits will expose students to research career pathways they might not otherwise encounter.
Internationally, the PI's established outreach programs in Nepal - such as the Particle Physics Masterclass and the BCVSPIN Conference - serve as a foundation for global engagement that enhances institutional visibility and collaborative opportunities. These activities, together with the proposed project, will contribute to the long-term growth of research excellence at Washington College by establishing a sustainable, undergraduate-focused particle physics group. The initiative will foster a vibrant and inclusive research culture while preparing students from a wide range of backgrounds for future success in science and technology fields.