서울대학교 중앙도서관
S-Space 소개
My S-Space
로그인이 필요합니다.
Login

S-Space

Publications

Detailed Information

Search for Bosonic Decay Modes of a Charged Higgs Boson in Rare Top Quark Decays : 탑 쿼크 희귀 붕괴에서 생성되는 하전 힉스 보존의 보존형 붕괴모드 탐색

DC Field Value Language
dc.contributor.advisor양운기-
dc.contributor.author변지환-
dc.date.accessioned2023-11-20T04:48:18Z-
dc.date.available2023-11-20T04:48:18Z-
dc.date.issued2023-
dc.identifier.other000000178726-
dc.identifier.urihttps://hdl.handle.net/10371/197275-
dc.identifier.urihttps://dcollection.snu.ac.kr/common/orgView/000000178726ko_KR
dc.description학위논문(박사) -- 서울대학교대학원 : 자연과학대학 물리·천문학부(물리학전공), 2023. 8. 양운기.-
dc.description.abstractThe thesis consists of a search for bosonic decay modes of charged Higgs bosons (H+) in rare top quark decays. The analysis is based on the data of proton-proton collisions at a center-of-mass energy of 13TeV, collected using the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC) in Conseil Europeen pour la Recherche Nucleaire (CERN) in 2016. The integrated luminosity of the used data corresponds to 35.9 /fb. The analysis looks for the production of H+ bosons in top quark pair events, the main production channel of top quarks at the LHC, to test the presence of extended Higgs sectors to the standard model of the particle physics. The H+ boson can decay to a W and CP-odd Higgs (A) boson pair with a large branching fraction, and this decay mode is investigated using a subsequent A decay mode, A→μ+μ-. Final states with electron-dimuon or trimuon, and at least two jets, including a b-tagged jet, are analyzed to search for the hypothetical process with the mass of A bosons between 15 and 75 GeV, and that of H+ bosons between 100 and 160 GeV. No statistically significant evidence of the additional Higgs bosons was found, and the first upper limits at 95% confidence level were set on the combined branching fraction for the decay chain, t→bH+→bW+A→bW+μ+μ-, between 1.9E-6 to 8.6E-6.-
dc.description.abstract이 논문은 탑 쿼크의 희귀 붕괴에서 유래하는 하전 힉스 보존 (H+)에 대한 탐색 연구로 이루어져 있다. 이 분석은 2016년에 유럽 핵입자 물리 연구소 (CERN)의 대형 강입자 충돌기 (LHC) 내에 위치한 소형 뮤온 솔레노이드 (CMS) 검출기를 이용해 얻어진 질량중심 에너지 13TeV 에서의 양성자-양성자 충돌 실험 결과를 바탕으로 얻어졌다. 사용된 데이터의 적분 광도는 35.9 /fb 에 해당한다. LHC에서 탑 쿼크의 주 생성 방식인 탑 쿼크 쌍생성 사건에서 생성되는 하전 힉스를 찾아서, 입자물리학의 표준모형에서 확장된 힉스 영역이 있는지 확인하고자 했다. 이 H+ 보존은 상당한 붕괴율로 W와 CP-홀수 힉스 (A) 보존쌍으로 붕괴할 수 있으며, A 보존의 연쇄 붕괴 모드, A→μ+μ−, 를 이용하여 이 H+ 보존의 보존형 붕괴 모드의 유무를 조사하였다. 전자-두 뮤온 또는 세 뮤온, 그리고 b-표지 제트를 포함한 두 개 이상의 제트들이 있는 최종 상태들을 분석하여, A 보존 질량 15에서 75 GeV 사이와 H+ 보존 질량 100에서 160 GeV 사이 영역에서 이 가설적 과정을 찾아보았다. 통계적으로 유의미한 추가적인 힉스 보존의 증거는 발견되지 않았으며, 이 연쇄 붕괴의 (t→bH+→bW+A→bW+μ+μ-) 종합 붕괴율에 95% 신뢰수준의 상한을 최초로 1.9E-6와 8.6E-6 사이에서 세웠다.-
dc.description.tableofcontentsChapter 1 Introduction 1
1.1 The Standard Model and Necessity for a New Theory 1
1.2 Charged Higgs Bosons - Quests for the Nature of Mass 3
1.3 Overview of the Thesis 6
Chapter 2 Phenomenological Background 7
2.1 Overview of the Standard Model 7
2.1.1 Particle Spectra in the SM 7
2.1.2 Gauge Symmetries in the SM 8
2.1.3 Origin of Mass in the SM 12
2.2 Phenomenology of 2HDM 19
2.2.1 Scalar Potentials and the Higgs Spectrum 19
2.2.2 Yukawa Interactions in the 2HDM 24
2.2.3 Gauge interactions of Higgs bosons in the 2HDM 27
2.2.4 Production and Decay Rates of Higgs Bosons 29
2.2.5 Experimental Constraints 37
Chapter 3 Experiment 45
3.1 Large Hadron Collider 45
3.1.1 Design 46
3.1.2 Injection Chain 50
3.1.3 Performance 52
3.2 Compact Muon Solenoid Detector 53
3.2.1 Magnet 54
3.2.2 Inner Tracking System 55
3.2.3 Electromagnetic Calorimeter 58
3.2.4 Hadronic Calorimeter 60
3.2.5 Muon Detection System 62
3.3 Trigger 65
3.3.1 Level-1 Trigger 66
3.3.2 High Level Trigger 70
3.4 Luminosity Measurement 72
Chapter 4 Data Analysis 76
4.1 Data Sets and Simulation 76
4.1.1 Data Sets 76
4.1.2 Modeling of Simulated Processes 77
4.2 Event Reconstruction 83
4.2.1 Vertex and Track 83
4.2.2 Particle Flow Algorithm 85
4.2.3 Jet 90
4.2.4 Missing Transverse Momentum 91
4.3 Object Selection 93
4.3.1 Primary Vertex 93
4.3.2 Muon 93
4.3.3 Electron 97
4.3.4 Jet 102
4.3.5 Missing Transverse Momentum 105
4.4 Trigger Selection 107
4.4.1 Selection Strategy 107
4.4.2 Efficiency Measurement 108
4.4.3 Trigger Efficiency Correction 114
4.4.4 Validation of Corrections on Physics Objects 117
4.5 Event Selection 120
4.5.1 Baseline Selection 120
4.5.2 Selections Dependent on Signal Hypotheses 124
4.6 Background Estimation 133
4.6.1 Jet-induced Nonprompt Leptons 133
4.6.2 Conversion Leptons 140
4.6.3 Prompt Leptons 142
4.6.4 Validation of Background Estimation 143
4.6.5 Linear Approximation of Background Distributions 148
4.7 Systematic Uncertainty 150
4.7.1 Uncertainty Sources and Treatments 150
4.7.2 Impact of Systematic Uncertainty 156
4.8 Result 159
4.8.1 Event Rates and Variable Distributions 159
4.8.2 Upper Limits on Signal Decay Rates 160
Chapter 5 Conclusion 166
Appendix A Acceptance Interpolation 181
Appendix B Fake Rate: Closure Test 184
Appendix C Dimuon Mass Distributions 185
Appendix D Upper Limits on Signal Rates 186
초록 188
Acknowledgements 189		-
dc.format.extentxiv, 190-
dc.language.isoeng-
dc.publisher서울대학교 대학원-
dc.subjectcharged Higgs boson-
dc.subjectCP-odd Higgs boson-
dc.subjecttop quark-
dc.subjectCMS-
dc.subject.ddc523.01-
dc.titleSearch for Bosonic Decay Modes of a Charged Higgs Boson in Rare Top Quark Decays-
dc.title.alternative탑 쿼크 희귀 붕괴에서 생성되는 하전 힉스 보존의 보존형 붕괴모드 탐색-
dc.typeThesis-
dc.typeDissertation-
dc.contributor.AlternativeAuthorBhyun Ji Hwan-
dc.contributor.department자연과학대학 물리·천문학부(물리학전공)-
dc.description.degree박사-
dc.date.awarded2023-08-
dc.identifier.uciI804:11032-000000178726-
dc.identifier.holdings000000000050▲000000000058▲000000178726▲-
Appears in Collections:
Files in This Item:

Altmetrics

Item View & Download Count

Show Simple Item Record
Find it @ SNU

  • mendeley

Items in S-Space are protected by copyright, with all rights reserved, unless otherwise indicated.

Share

qrcode
SNS Share