Higgs and collider phenomenology of physics beyond the standard model
Higgs and collider phenomenology of physics beyond the standard model
This thesis explores three classes of beyond-the-Standard Model (BSM) theories: Minimal Universal Extra Dimensions (MUED), the 4D Composite Higgs Model (4DCHM) and Technicolor. In particular, Higgs boson data from the Large Hadron Collider (LHC) is used to test the viability of these models and constrain their parameter spaces. It turns out that this provides a valuable constraint for MUED, requiring that the compactification scale R-1 of the theory be greater than 500 GeV. More direct searches for MUED are also considered, and the creation of a software implementation of MUED in CalcHEP is discussed. This implementation is used to determine that the tri-lepton final state is the most promising discovery signature due to the high lepton multiplicity in MUED and that the exclusion reach of MUED using this signature is up to R-1 = 1200 GeV with 20 fb-1 of data from the 8 TeV LHC. The 4DCHM is also analysed in light of the Higgs data. It is found that, once direct detection constraints are applied, the model is actually a slightly better fit to Higgs data than the Standard Model for most points in the 4DCHM parameter space considered. Finally, various Technicolor models are tested against Higgs data using a more sophisticated statistical analysis and it is found that most provide viable Higgs boson candidates with broadly Standard-Model like couplings.
Brown, Matthew
177a0c56-a484-440b-8518-b4b9872521a1
November 2013
Brown, Matthew
177a0c56-a484-440b-8518-b4b9872521a1
Belyaev, Alexander
6bdb9638-5ff9-4b65-a8f2-34bae3ac34b3
Brown, Matthew
(2013)
Higgs and collider phenomenology of physics beyond the standard model.
University of Southampton, Physical Sciences and Engineering, Doctoral Thesis, 161pp.
Record type:
Thesis
(Doctoral)
Abstract
This thesis explores three classes of beyond-the-Standard Model (BSM) theories: Minimal Universal Extra Dimensions (MUED), the 4D Composite Higgs Model (4DCHM) and Technicolor. In particular, Higgs boson data from the Large Hadron Collider (LHC) is used to test the viability of these models and constrain their parameter spaces. It turns out that this provides a valuable constraint for MUED, requiring that the compactification scale R-1 of the theory be greater than 500 GeV. More direct searches for MUED are also considered, and the creation of a software implementation of MUED in CalcHEP is discussed. This implementation is used to determine that the tri-lepton final state is the most promising discovery signature due to the high lepton multiplicity in MUED and that the exclusion reach of MUED using this signature is up to R-1 = 1200 GeV with 20 fb-1 of data from the 8 TeV LHC. The 4DCHM is also analysed in light of the Higgs data. It is found that, once direct detection constraints are applied, the model is actually a slightly better fit to Higgs data than the Standard Model for most points in the 4DCHM parameter space considered. Finally, various Technicolor models are tested against Higgs data using a more sophisticated statistical analysis and it is found that most provide viable Higgs boson candidates with broadly Standard-Model like couplings.
More information
Published date: November 2013
Organisations:
University of Southampton, Physics & Astronomy
Identifiers
Local EPrints ID: 365147
URI: http://eprints.soton.ac.uk/id/eprint/365147
PURE UUID: 5ae8230d-3dec-4ee8-ab14-1e12c3356443
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Date deposited: 03 Jun 2014 09:13
Last modified: 15 Mar 2024 03:28
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Contributors
Author:
Matthew Brown
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