<p> A search for Higgs boson pair production in the four b-jet final state is carried out with up to 36.1/fb of LHC proton--proton collision data collected at √<i>s</i> = 13 TeV with the ATLAS detector in 2015 and 2016. Three benchmark signals are studied: a spin-2 graviton decaying into a Higgs boson pair, a scalar resonance decaying into a Higgs boson pair, and Standard Model non-resonant Higgs boson pair production. This thesis presents a search in events with four individually resolved b-tagged jets. Higgs bosons produced with large momenta are reconstructed as single large radius jets with substructure. The analysis of this topology is presented in CERN-THESIS-2018-118. The two analyses are statistically combined and upper limits on the production cross section of Higgs boson pairs times branching ratio to four b-quarks are set in each model. The combined result searches for resonance masses in the range 260–3000 GeV. No significant excess is observed; the largest deviation of data over prediction is found at a mass of 280 GeV, corresponding to 2.3 standard deviations globally. The observed 95% confidence level upper limit on the non-resonant production is 13 times the Standard Model prediction.</p><p>
| Identifer | oai:union.ndltd.org:PROQUEST/oai:pqdtoai.proquest.com:10974446 |
| Date | 01 January 2019 |
| Creators | Bryant, Patrick |
| Publisher | The University of Chicago |
| Source Sets | ProQuest.com |
| Language | English |
| Detected Language | English |
| Type | thesis |
Page generated in 0.0559 seconds