博碩士論文 101222017 詳細資訊




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姓名 麥書豪(Shu-Hao Mai)  查詢紙本館藏   畢業系所 物理學系
論文名稱 在質子對撞能量8TeV下尋找具有雙電子雙渺子末態的激發態輕子
(Search for excited leptons in the 2e2μ final state in pp collisions at $sqrt{s}$ = 8 TeV)
相關論文
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★ Measurement of Zγ production in 5 fb-1 of pp collisions at √s = 7 TeV with the CMS detector★ Search for a Higgs boson decaying into γ∗γ → eeγ in pp collisions at √s = 8 TeV with the CMS detector
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★ Search for a Higgs boson decay into γ*γ→μμγ in pp collisions at √s = 13 TeV
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摘要(中) 我們在此呈現一次針對激發態輕子於2e2μ末態之搜尋結果。此分析為CMS實驗在尋找激發態輕子於四輕子末態實驗之部分。此次實驗利用LHC於√s = 8 TeV撞擊之數據。數據的蒐集由CMS偵測器完成,使用數據之累積照度達到19.7 fb-1。激發態輕子(l^*)預期將透過接觸相互作用與一標準模型之輕子伴隨生成。而後,激發態輕子將以l^*→lZ→lll (l=e,μ)的機制衰變,造成四輕子之末態。這是LHC第一個針對激發態輕子於四輕子末態之搜尋。實驗結果並未超出標準模型背景的預期。激發態輕子的預期生成截面積受到T_3耦合因子f以及Y耦合因子f′的選擇影響。對於2e2μ之末態,當f/f^′=1 (f/f^′=-1)及在Λ=M_(l^*)時,激發態電子與渺子之質量上限皆設在1.60(1.85) TeV於95%的信心水準。結合4e與4μ之實驗結果,激發態電子與渺子之質量上限可分別設在1.70(1.95) TeV以及1.75(2.00) TeV。
摘要(英) A search of excited lepton in 2e2μ fi nal state is performed using a data sample of pp collisions at a center-of-mass energy √s = 8 TeV collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 19.7 fb-1. This is a part of the excited lepton search in 4-lepton final state in CMS. Excited leptons (l^*) are assumed to be produced via contact interactions in conjunction with a standard model lepton and to decay via l^*→lZ→lll (l=e,μ), yielding a fi nal state with four
leptons. We present the first study of the search for excited lepton in 4-lepton fi nal state at LHC. No signi cant excess is observed in the data above the expected standard model background. The expect cross section of l^*can be signi cantly aff ected by diff erent choice of coupling constant f and f′ to T_3 and Y. For f/f′=1(f/f′=-1),
upper bounds at 95% confi dence level are set to 1.60(1.85) TeV for both e^* and μ^* in 2e2μfi nal state with Λ=M_(l^*). Combining these results with 4e and 4μ channels, the limits can be set to 1.70(1.95) TeV and 1.75(2.00) TeV for e^* and μ^*, respectively.
關鍵字(中) ★ 激發態輕子
★ 標準模型外物理
★ 基本粒子
★ 緊湊渺子線圈
★ 大強子對撞機
關鍵字(英) ★ excited lepton
★ beyond standard model
★ elementary particle
★ CMS
★ LHC
論文目次 1 Introduction and theory overview 1
1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Theory overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2.1 Model of excited leptons . . . . . . . . . . . . . . . . . . . . . 2
1.2.2 Decay of excited leptons . . . . . . . . . . . . . . . . . . . . . 5
1.2.3 Production of excited leptons . . . . . . . . . . . . . . . . . . 8
2 CMS detector and LHC 11
2.1 Large Hadron Collider . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.2 CMS detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.2.1 Coordinate in CMS . . . . . . . . . . . . . . . . . . . . . . . . 13
2.2.2 Superconduction solenoid . . . . . . . . . . . . . . . . . . . . 14
2.2.3 Tracking system . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.2.4 Electromagnetic calorimeter . . . . . . . . . . . . . . . . . . . 17
2.2.5 Hadron calorimeter . . . . . . . . . . . . . . . . . . . . . . . . 17
2.2.6 Muon chamber . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.3 Trigger system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3 Analysis Procedures 23
3.1 Data and Monte Carlo samples . . . . . . . . . . . . . . . . . . . . . 23
3.1.1 Data samples . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.1.2 Monte Carlo samples . . . . . . . . . . . . . . . . . . . . . . . 23
3.2 Trigger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3.3 Object reconstruction and identifi cation . . . . . . . . . . . . . . . . 28
3.3.1 Electron reconstruction . . . . . . . . . . . . . . . . . . . . . . 28
3.3.2 Electron identifi cation . . . . . . . . . . . . . . . . . . . . . . 30
3.3.3 Muon reconstruction . . . . . . . . . . . . . . . . . . . . . . . 33
3.3.4 Muon identifi cation . . . . . . . . . . . . . . . . . . . . . . . . 34
3.3.5 Pileup Reweighting . . . . . . . . . . . . . . . . . . . . . . . . 38
3.4 Event selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
3.4.1 Analysis strategy . . . . . . . . . . . . . . . . . . . . . . . . . 39
3.4.2 Background estimation . . . . . . . . . . . . . . . . . . . . . . 44
3.5 Systematic uncertainties . . . . . . . . . . . . . . . . . . . . . . . . . 53
4 Results and conclusion 56
4.1 Cross section limit computation . . . . . . . . . . . . . . . . . . . . . 56
4.2 Optimization of the final selection . . . . . . . . . . . . . . . . . . . . 57
4.3 Limit computation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
4.3.1 Limits of excited muons  for f = f′ = 1 . . . . . . . . . . . 60
4.3.2 Limits of excited electrons e for f = f′ = 1 . . . . . . . . . . 61
4.3.3 Limits for excited leptons  for f = f′ = -1 . . . . . . . . 63
4.3.4 Limits of excited leptons e for f = f′ = -1 . . . . . . . . . 63
4.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
參考文獻 [1] CDF Collaboration. Search for excited and exotic electrons in the egamma decay channel in pp collisions at sqrt{s}=1.96 tev. Phys. Rev. Lett., 94:101802, 2005.
[2] CDF Collaboration. Search for excited and exotic electrons in the mugamma decay channel in pp collisions at sqrt{s}=1.96 tev. Phys. Rev. Lett., 97:191802, 2006.
[3] D0 Collaboration. Search for excited muons in pp collisions at sqrt{s}=1.96 tev.
Phys. Rev., D73:111102, 2006.
[4] D0 Collaboration. Search for excited electrons in pp collisions at sqrt{s}=1.96 tev.
Phys. Rev., D77:091102, 2008.
[5] Exotica Resonances Group. Physicsresults exo10016.
https://twiki.cern.ch/twiki/bin/view/CMSPublic/PhysicsResultsEXO10016.
[6] Sunanda Banerjee, Satyaki Bhattacharya, and Shilpi Jain. Search for excited electron in pp collisions at sqrt{s}=7 tev in the cms experiment with 4.7 fb-1 of
data. CMS Analysis Note: AN-11-452, 2012.
[7] J. Caudron, K. Hoepfner, I. Svintradze1, Y. Maravin, C.-M. Kuo, and S. Bahinipati. Search for excited muons in proton-proton collisions at sqrt{s}=7 tev with the cms detector. CMS Analysis Note: AN-12-013, 2012.
[8] ATLAS Collaboration. Search for excited leptons in proton-proton collisions at
sqrt(s) = 7 TeV with the ATLAS detector. 2012.
[9] J. Pati and A. Salam. Lepton number as the fourth color. Phys. Rev. D,
10:275, 1974.
[10] U. Baur, M. Spira, and P.M. Zerwas. Excited-quark and -lepton production at hadron colliders. Phys. Rev. D, 42:815, 1990.
[11] E.J. Eichten, K.D. Lane, and M.E. Peskin. New tests for quark and lepton substructure. Phys. Rev. Lett., 50:811, 1983.
[12] Torbjorn Sjostrand, Stephen Mrenna, and Peter Z. Skands. PYTHIA 6.4
Physics and Manual. JHEP, 05:026, 2006.
[13] K. Hagiwara and K. Hikasa. Searches for quark and lepton compositeness. The European Physical Journal C - Particles and Fields, 15(1-4):852{860, 2000.
[14] Lyndon Evans and Philip Bryant. Lhc machine. Journal of Instrumentation, 3(08):S08001, 2008.
[15] CMS Collaboration. Physics TDR volume I, The CMS Physics Technical Design R I. CERN-LHCC-2006-001, page 521pp, 2006.
[16] CMS Collaboration. CMS technical design report, volume II: Physics
performance. J. Phys., G34:995{1579, 2007.
[17] CMS Collaboration. "cms luminosity based on pixel cluster counting - summer
2013 update". "CMS PAS LUM-13-001", 2013.
[18] John Allison et al. Geant4 developments and applications. IEEE Trans. Nucl.
Sci., 53:270, 2006.
[19] Johan Alwall et al. MadGraph/MadEvent v4: the new web generation. JHEP,
09:028, 2007.
[20] Simone Alioli, Paolo Nason, Carlo Oleari, and Emanuele Re. NLO vector-boson
production matched with shower in POWHEG. JHEP, 07:060, 2008.
[21] Swapan Majhi. QCD corrections to excited lepton (pair)production at LHC.
2012.
[22] W Adam, R Frhwirth, A Strandlie, and T Todorov. Reconstruction of electrons
with the gaussian-sum lter in the cms tracker at the lhc. Journal of Physics
G: Nuclear and Particle Physics, 31(9):N9, 2005.
[23] Wolfgang Adam, Boris Mangano, Thomas Speer, and Teddy Todorov. Track
Reconstruction in the CMS tracker. Technical Report CMS-NOTE-2006-041,
CERN, Geneva, Dec 2006.
[24] H. Bethe and W. Heitler. On the stopping of fast particles and on the creation
of positive electrons. Proceedings of the Royal Society of London. Series A,
146(856):83{112, 1934.
[25]
https://twiki.cern.ch/twiki/bin/viewauth/CMS/EgCommissioningAndPhysicsDeliverables.
[26] https://twiki.cern.ch/twiki/bin/view/CMS/HEEPElectronID.
[27] https://twiki.cern.ch/twiki/bin/viewauth/CMS/BoostedZToEEModIso.
[28] https://twiki.cern.ch/twiki/bin/viewauth/CMS/HEEPEciencies.
[29] Performance of muon identi cation in pp collisions at s**0.5 = 7 TeV.
Technical Report CMS-PAS-MUO-10-002, CERN, 2010. Geneva, 2010.
[30] Exotica Muon Group. High pt muons.
https://twiki.cern.ch/twiki/bin/viewauth/CMS/ExoticaExcitedMuon.
[31] https://twiki.cern.ch/twiki/bin/view/CMS/MuonReferenceE s.
[32] https://twiki.cern.ch/twiki/bin/view/CMS/MuonReferenceResolution.
[33] https://twiki.cern.ch/twiki/bin/view/CMSPublic/SWGuideMuonId.
[34] https://twiki.cern.ch/twiki/bin/view/CMS/MuonTagAndProbe.
[35] The CMS Collaboration. Search for narrow spin-2 resonance decaying to Z bosons in the semileptonic fi nal state. http://cds.cern.ch/record/1596494, 2013.
[36] https://twiki.cern.ch/twiki/bin/view/CMS/PileupMCReweightingUtilities.
[37] I. Puljak E. Di Marco. Measurement of the production and decay of a higgs
boson in the four-lepton nal state. CMS Analysis Note: AN-13-108, 2013.
[38] CMS Collaboration. Ecal detector performance, 2011 data. CMS Performance
Note: DP-12-007, 2012.
[39] Zprime group. Search for heavy resonances in dileptons. CMS Analysis Note:
AN-12-415, 2012.
[40] The CMS Collaboration. Measurement of the w+w- and zz production cross section in pp collisions at sqrt{s} = 8 tev. 2013.
[41] https://twiki.cern.ch/twiki/bin/view/CMS/PileupSystematicErrors.
[42] G. K. et. al. Roostatscl95: cross section in a counting experiment.
https://twiki.cern.ch/twiki/bin/viewauth/CMS/RooStatsCl95.
[43] Higgs Statistic Group. Documentation of the roostats-based statistics tools for
higgs pag.
https://twiki.cern.ch/twiki/bin/viewauth/CMS/SWGuideHiggsAnalysisCombinedLimit.
指導教授 郭家銘(Chia-Ming Kuo) 審核日期 2014-10-7
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