Full Text Available

Note: Clicking the button above will open the full text document at the original institutional repository in a new window.

Single top channel in association with H→bb̄ production at ATLAS : a feasible study

A degeneracy in the minima of the profile likelihood function of the Higgs boson coupling to fermions and bosons, where boson couplings are assumed to be positive, is reported by both ATLAS and CMS. Although one minimum lies in the region of positive fermionic coupling scale factors, consistent with...

Full description

Saved in:
Bibliographic Details
Main Author: Antel, Claire
Other Authors: Hamilton, Andrew
Format: Thesis
Language:English
Published: Department of Physics 2015
Subjects:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1867614265012125696
access_status_str Open Access
author Antel, Claire
author2 Hamilton, Andrew
author_browse Antel, Claire
Hamilton, Andrew
author_facet Hamilton, Andrew
Antel, Claire
author_sort Antel, Claire
collection Thesis
description A degeneracy in the minima of the profile likelihood function of the Higgs boson coupling to fermions and bosons, where boson couplings are assumed to be positive, is reported by both ATLAS and CMS. Although one minimum lies in the region of positive fermionic coupling scale factors, consistent with the Standard Model, the second minimum lies in the negative region-a region which would indicate new physics. This degeneracy can potentially be resolved by studying a fermionic-bosonic interference that takes place in the single top quark production in association with a Higgs particle, in which the cross-section is significantly enhanced for anomalous coupling values. A truth level feasibility study of the tH process with H→bb̄ is conducted at 8 TeV and 21 fb-¹ of integrated luminosity. the equivalent of the 2012 run at the LHC. A sensitivity of l.7σ is found for the enhanced case of a coupling scale factor of cF = -1. This is insufficient for a detection. A projection to 14 TeV centre-of-mass energies indicates that at truth-level a 3σ significance with 15 fb-¹ of integrated luminosity can be reached for the enhanced case. However, assuming as low as 5% systematic uncertainty lowers this to below 2σ across the whole luminosity range, indicating that the upcoming run at LHC will also be insufficient to resolve the degeneracy.
format Thesis
id oai:open.uct.ac.za:11427/15768
institution University of Cape Town (South Africa)
language eng
last_indexed 2026-06-10T12:49:17.496Z
license_str Not specified — see source repository
provenance_str_mv Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository
publishDate 2015
publishDateRange 2015
publishDateSort 2015
publisher Department of Physics
publisherStr Department of Physics
record_format dspace
source_str UCTD — University of Cape Town Open Access Repository
spelling oai:open.uct.ac.za:11427/15768 Single top channel in association with H→bb̄ production at ATLAS : a feasible study Antel, Claire Hamilton, Andrew Gray, Heather M Physics A degeneracy in the minima of the profile likelihood function of the Higgs boson coupling to fermions and bosons, where boson couplings are assumed to be positive, is reported by both ATLAS and CMS. Although one minimum lies in the region of positive fermionic coupling scale factors, consistent with the Standard Model, the second minimum lies in the negative region-a region which would indicate new physics. This degeneracy can potentially be resolved by studying a fermionic-bosonic interference that takes place in the single top quark production in association with a Higgs particle, in which the cross-section is significantly enhanced for anomalous coupling values. A truth level feasibility study of the tH process with H→bb̄ is conducted at 8 TeV and 21 fb-¹ of integrated luminosity. the equivalent of the 2012 run at the LHC. A sensitivity of l.7σ is found for the enhanced case of a coupling scale factor of cF = -1. This is insufficient for a detection. A projection to 14 TeV centre-of-mass energies indicates that at truth-level a 3σ significance with 15 fb-¹ of integrated luminosity can be reached for the enhanced case. However, assuming as low as 5% systematic uncertainty lowers this to below 2σ across the whole luminosity range, indicating that the upcoming run at LHC will also be insufficient to resolve the degeneracy. 2015-12-10T09:35:35Z 2015-12-10T09:35:35Z 2015 Master Thesis Masters MSc http://hdl.handle.net/11427/15768 eng application/pdf Department of Physics Faculty of Science University of Cape Town
spellingShingle Physics
Antel, Claire
Single top channel in association with H→bb̄ production at ATLAS : a feasible study
thesis_degree_str Master's
title Single top channel in association with H→bb̄ production at ATLAS : a feasible study
title_full Single top channel in association with H→bb̄ production at ATLAS : a feasible study
title_fullStr Single top channel in association with H→bb̄ production at ATLAS : a feasible study
title_full_unstemmed Single top channel in association with H→bb̄ production at ATLAS : a feasible study
title_short Single top channel in association with H→bb̄ production at ATLAS : a feasible study
title_sort single top channel in association with h bb production at atlas a feasible study
topic Physics
url http://hdl.handle.net/11427/15768
work_keys_str_mv AT antelclaire singletopchannelinassociationwithhbbproductionatatlasafeasiblestudy