Piecing together the Standard Model H → WW∗ semi-leptonic decay in ATLAS

Maurin, Théo (2026) Piecing together the Standard Model H → WW∗ semi-leptonic decay in ATLAS. PhD thesis, University of Glasgow.

Abstract

This thesis presents the design of a novel analysis searching for the previously unexplored Standard Model H → WW∗ semi-leptonic final state, considering both the ggF and VBF Higgs production modes. The phenomenology study that laid the foundation for the analysis is presented, and the experimental adaptations and improvements are subsequently detailed. The expected 95% CLs upper limit on the signal strength is found to be µs = 1.804+0.715 −0.512 for an integrated luminosity of 140 fb−1, which corresponds to the ATLAS data accumulated during Run 2. Projections to the HL-LHC integrated luminosity indicate that a 5σ observation of the channel is achievable, provided the dominant systematic uncertainty arising from the lack of MC statistics for background processes is mitigated. In addition, relevant contributions to flavour tagging within ATLAS and improvements to the Neutrino Weighting algorithm are presented and discussed.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Subjects: Q Science > QC Physics
• Colleges/Schools: College of Science and Engineering > School of Physics and Astronomy
• Funder's Name: The Royal Society (ROYSOC)
• Supervisor's Name: Howarth, Professor James
• Date of Award: 2026
• Depositing User: Theses Team
• Unique ID: glathesis:2026-86192
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 21 Aug 2026 14:15
• Last Modified: 21 Aug 2026 14:20
• Thesis DOI: 10.5525/gla.thesis.86192
• URI: https://theses.gla.ac.uk/id/eprint/86192