A Search for Neutral Long-Lived Particles Decaying into Displaced Jets in the ATLAS Calorimeter in Proton-Proton Collisions at the LHC

dc.contributor.advisor	Watts, Gordon
dc.contributor.author	Proffitt, Mason
dc.date.accessioned	2025-08-01T22:30:00Z
dc.date.available	2025-08-01T22:30:00Z
dc.date.issued	2025-08-01
dc.date.submitted	2025
dc.description	Thesis (Ph.D.)--University of Washington, 2025
dc.description.abstract	A search for neutral long-lived particles (LLPs) decaying in the ATLAS hadronic calorimeter using 140 fb^-1 of proton proton collisions at √s = 13 TeV delivered by the LHC is presented. The analysis targets pair-produced LLPs where at least one LLP is produced with sufficiently low boost that its decay products can be resolved as separate jets. No excesses of events relative to the background predictions are observed. Higgs boson branching fractions to pairs of hadronically decaying neutral LLPs larger than 1% are excluded at 95% confidence level for proper decay lengths in the range of 30 cm to 4.5 m depending on the LLP mass, a factor of three improvement on previous searches in the hadronic calorimeter.
dc.embargo.terms	Open Access
dc.format.mimetype	application/pdf
dc.identifier.other	Proffitt_washington_0250E_28364.pdf
dc.identifier.uri	https://hdl.handle.net/1773/53736
dc.language.iso	en_US
dc.rights	none
dc.subject	Physics
dc.subject.other	Physics
dc.title	A Search for Neutral Long-Lived Particles Decaying into Displaced Jets in the ATLAS Calorimeter in Proton-Proton Collisions at the LHC
dc.type	Thesis

Files

Now showing 1 - 1 of 1