Search for the H → bb Decay of the Standard Model Higgs Boson in Associated Production with Vector Bosons Using ATLAS Data at √s = 8 TeV
Search for the H → bb Decay of the Standard Model Higgs Boson in Associated Production with Vector Bosons Using ATLAS Data at √s = 8 TeV
dc.contributor.advisor | Wermes, Norbert | |
dc.contributor.author | Hageböck, Stephan | |
dc.date.accessioned | 2020-04-25T12:05:19Z | |
dc.date.available | 2020-04-25T12:05:19Z | |
dc.date.issued | 29.10.2018 | |
dc.identifier.uri | https://hdl.handle.net/20.500.11811/7645 | |
dc.description.abstract | In this thesis, a search for the H → bb decay of the Standard Model Higgs boson is presented. A dataset of 20.2 fb-1 recorded by the ATLAS detector at CERN is searched for events where Higgs bosons are produced in association with a vector boson that decays to charged leptons at a centre-of-mass energy of √s = 8 TeV. Machine learning with boosted decision trees is used to implement the most sensitive V H → V bb search on √s = 8 TeV LHC data with charged leptons, the ATLAS search published in 2015. It is further shown that the machine-learning part of this search can be improved by training boosted decision trees with Lorentz-invariant observables, which increases the sensitivity by 10 %, and reduces systematic uncertainties by 16 %. For a Higgs boson of mH = 125 GeV, a local excess over the background prediction at 99.2 % confidence level is observed, which corresponds to a discovery significance of 2.4 σ, whereas 1.9 σ were expected from simulations. The ratio of the observed signal strength compared to the Standard Model prediction is μ = 1.3 +0.7 -0.6. | en |
dc.language.iso | eng | |
dc.rights | In Copyright | |
dc.rights.uri | http://rightsstatements.org/vocab/InC/1.0/ | |
dc.subject | Teilchenphysik | |
dc.subject | Elementarteilchenphysik | |
dc.subject | Higgs | |
dc.subject | CERN | |
dc.subject | ATLAS | |
dc.subject | b-Quark | |
dc.subject | Higgs-Zerfall | |
dc.subject | Assoziierte Produktion | |
dc.subject | Vektorboson | |
dc.subject | Particle Physics | |
dc.subject | Elementary Particles | |
dc.subject | Higgs Boson | |
dc.subject | Higgs decay | |
dc.subject | Associated production | |
dc.subject | Vector bosons | |
dc.subject.ddc | 530 Physik | |
dc.title | Search for the H → bb Decay of the Standard Model Higgs Boson in Associated Production with Vector Bosons Using ATLAS Data at √s = 8 TeV | |
dc.type | Dissertation oder Habilitation | |
dc.publisher.name | Universitäts- und Landesbibliothek Bonn | |
dc.publisher.location | Bonn | |
dc.rights.accessRights | openAccess | |
dc.identifier.urn | https://nbn-resolving.org/urn:nbn:de:hbz:5n-52108 | |
ulbbn.pubtype | Erstveröffentlichung | |
ulbbnediss.affiliation.name | Rheinische Friedrich-Wilhelms-Universität Bonn | |
ulbbnediss.affiliation.location | Bonn | |
ulbbnediss.thesis.level | Dissertation | |
ulbbnediss.dissID | 5210 | |
ulbbnediss.date.accepted | 03.09.2018 | |
ulbbnediss.institute | Mathematisch-Naturwissenschaftliche Fakultät : Fachgruppe Physik/Astronomie / Physikalisches Institut (PI) | |
ulbbnediss.fakultaet | Mathematisch-Naturwissenschaftliche Fakultät | |
dc.contributor.coReferee | Brock, Ian C. |
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