Investigation of non-resonant HH production and couplings in the bbbb final state using the ATLAS detector
The full Run 2 ATLAS HH → bbbb analysis targeted the simultaneous non-resonant production of two Higgs bosons (HH) in the bbbb final state. This analysis utilised 126 fb^-1 of 13 TeV proton-proton collision data from the ATLAS Experiment on CERN’s Large Hadron Collider. The increase in data, alongsi...
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| Médium: | Diplomová práce |
| Jazyk: | English |
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2022
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| _version_ | 1826309438224465920 |
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| author | Grundy, JC |
| author2 | Huffman, B |
| author_facet | Huffman, B Grundy, JC |
| author_sort | Grundy, JC |
| collection | OXFORD |
| description | The full Run 2 ATLAS HH → bbbb analysis targeted the simultaneous non-resonant production of two Higgs bosons (HH) in the bbbb final state. This analysis utilised 126 fb^-1 of 13 TeV proton-proton collision data from the ATLAS Experiment on CERN’s Large Hadron Collider. The increase in data, alongside a program of intensive research and development that I played a significant role in, produced a comprehensive set of important physics results that showed a marked improvement on predecessor ATLAS HH → bbbb analyses. An observed (expected) upper limit on HH production via Gluon-Gluon Fusion (ggF) and Vector Boson Fusion (VBF) was set at 5.4 (8.1) times the SM prediction at the 95% confidence level (CL). Constraints on the coupling modifiers κ_λ , κ_V and κ_2V (defined as κ = c/c_SM ) were set using two different statistical methods. Performing a comparison of the theoretical cross-section to the upper limit on HH production, κ_λ was constrained to −3.9 < κ_λ < 11.1 (−4.6 < κ_λ < 10.8) and κ_2V to −0.03 < κ_2V < 2.11 (−0.05 < κ_2V < 2.12) at the 95% CL. Performing a direct measurement of the log likelihood ratio, κ_λ was constrained to −3.5 < κ_λ < 11.3 (−5.4 < κ_λ < 11.4) and κ_2V to 0.0 < κ_2V < 2.1 (−0.1 < κ_2V < 2.1) at 2σ. Two-dimensional limits were also set on a range of values in κ_2V-κ_λ and κ_2V-κ_V space at the 95% CL, the former being the first of its kind. |
| first_indexed | 2024-03-07T07:35:41Z |
| format | Thesis |
| id | oxford-uuid:eee560e3-a681-4008-8ae8-687648e5b3c2 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T07:35:41Z |
| publishDate | 2022 |
| record_format | dspace |
| spelling | oxford-uuid:eee560e3-a681-4008-8ae8-687648e5b3c22023-02-23T12:11:07ZInvestigation of non-resonant HH production and couplings in the bbbb final state using the ATLAS detectorThesishttp://purl.org/coar/resource_type/c_db06uuid:eee560e3-a681-4008-8ae8-687648e5b3c2Particle PhysicsEnglishHyrax Deposit2022Grundy, JCHuffman, BWilkinson, GFacini, GThe full Run 2 ATLAS HH → bbbb analysis targeted the simultaneous non-resonant production of two Higgs bosons (HH) in the bbbb final state. This analysis utilised 126 fb^-1 of 13 TeV proton-proton collision data from the ATLAS Experiment on CERN’s Large Hadron Collider. The increase in data, alongside a program of intensive research and development that I played a significant role in, produced a comprehensive set of important physics results that showed a marked improvement on predecessor ATLAS HH → bbbb analyses. An observed (expected) upper limit on HH production via Gluon-Gluon Fusion (ggF) and Vector Boson Fusion (VBF) was set at 5.4 (8.1) times the SM prediction at the 95% confidence level (CL). Constraints on the coupling modifiers κ_λ , κ_V and κ_2V (defined as κ = c/c_SM ) were set using two different statistical methods. Performing a comparison of the theoretical cross-section to the upper limit on HH production, κ_λ was constrained to −3.9 < κ_λ < 11.1 (−4.6 < κ_λ < 10.8) and κ_2V to −0.03 < κ_2V < 2.11 (−0.05 < κ_2V < 2.12) at the 95% CL. Performing a direct measurement of the log likelihood ratio, κ_λ was constrained to −3.5 < κ_λ < 11.3 (−5.4 < κ_λ < 11.4) and κ_2V to 0.0 < κ_2V < 2.1 (−0.1 < κ_2V < 2.1) at 2σ. Two-dimensional limits were also set on a range of values in κ_2V-κ_λ and κ_2V-κ_V space at the 95% CL, the former being the first of its kind. |
| spellingShingle | Particle Physics Grundy, JC Investigation of non-resonant HH production and couplings in the bbbb final state using the ATLAS detector |
| title | Investigation of non-resonant HH production and couplings in the bbbb final state using the ATLAS detector |
| title_full | Investigation of non-resonant HH production and couplings in the bbbb final state using the ATLAS detector |
| title_fullStr | Investigation of non-resonant HH production and couplings in the bbbb final state using the ATLAS detector |
| title_full_unstemmed | Investigation of non-resonant HH production and couplings in the bbbb final state using the ATLAS detector |
| title_short | Investigation of non-resonant HH production and couplings in the bbbb final state using the ATLAS detector |
| title_sort | investigation of non resonant hh production and couplings in the bbbb final state using the atlas detector |
| topic | Particle Physics |
| work_keys_str_mv | AT grundyjc investigationofnonresonanthhproductionandcouplingsinthebbbbfinalstateusingtheatlasdetector |