Search for new physics using top quark pairs produced in association with a boosted Z or Higgs boson in effective field theory.
| dc.contributor.advisor | Hatakeyama, Kenichi. | |
| dc.creator | Caraway, Bryan David, 1993- | |
| dc.creator.orcid | 0000-0002-6088-2020 | |
| dc.date.accessioned | 2022-06-03T13:16:00Z | |
| dc.date.available | 2022-06-03T13:16:00Z | |
| dc.date.created | 2022-05 | |
| dc.date.issued | 2022-03-29 | |
| dc.date.submitted | May 2022 | |
| dc.date.updated | 2022-06-03T13:16:01Z | |
| dc.description.abstract | A data sample containing top quark pairs (t ̄t) produced in association with a boosted Z or Higgs boson is used to search for signs of new physics within the framework of effective field theory. The data correspond to an integrated luminosity of 138 fb−1 of proton-proton collisions produced at a center-of-mass energy of 13 TeV at the LHC and collected by the CMS experiment. Selected collision events contain a single lepton and hadronic jets, including two identified with the decay of bottom quarks, plus an additional large-radius jet with high transverse momentum identified as a Z or Higgs boson decaying to a bottom quark pair. Machine learning techniques are employed to discriminate t ̄tZ and t ̄tH events from background processes, which are dominated by t ̄t + jets production. The signal strengths of boosted t ̄tZ and t ̄tH processes are measured, and upper limits are placed on the t ̄tZ and t ̄tH differential cross sections as a function of the Z or Higgs boson transverse momentum. In addition, effects of physics beyond the standard model are probed using a framework in which the standard model is considered to be the low-energy effective field theory of a higher- scale theory. Eight possible dimension-six operators are added to the standard model Lagrangian and their corresponding coefficients are constrained via a fit to the data. | |
| dc.format.mimetype | application/pdf | |
| dc.identifier.uri | https://hdl.handle.net/2104/11930 | |
| dc.language.iso | en | |
| dc.rights.accessrights | Worldwide access | |
| dc.subject | Standard model. Effective field theory. Bosons. Quarks. Top. Higgs. Wilson coefficients. Neural network. Machine learning. CMS. LHC. CERN. | |
| dc.title | Search for new physics using top quark pairs produced in association with a boosted Z or Higgs boson in effective field theory. | |
| dc.type | Thesis | |
| dc.type.material | text | |
| thesis.degree.department | Baylor University. Dept. of Physics. | |
| thesis.degree.grantor | Baylor University | |
| thesis.degree.level | Doctoral | |
| thesis.degree.name | Ph.D. |
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