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| DC 欄位 | 值 | 語言 |
|---|---|---|
| dc.contributor.advisor | 熊怡 | zh_TW |
| dc.contributor.advisor | Yee Bob Hsiung | en |
| dc.contributor.author | 吳桐 | zh_TW |
| dc.contributor.author | TONG WU | en |
| dc.date.accessioned | 2024-08-16T16:35:56Z | - |
| dc.date.available | 2024-08-17 | - |
| dc.date.copyright | 2024-08-16 | - |
| dc.date.issued | 2024 | - |
| dc.date.submitted | 2024-08-14 | - |
| dc.identifier.citation | [1] Particle Data Group et al. “Review of Particle Physics”. In: Progress of Theoretical and Experimental Physics 2022.8 (Aug. 2022), p. 083C01. ISSN: 2050-3911. DOI: 10. 1093/ptep/ptac097.
[2] Marco Fabbrichesi, Emidio Gabrielli, and Gaia Lanfranchi. The Physics of the Dark Photon: A Primer. Springer International Publishing, 2021. ISBN: 9783030625191. DOI: 10.1007/978-3-030-62519-1. [3] Jhih-Ying Su and Jusak Tandean. “Kaon decays shedding light on massless dark photons”. In: The European Physical Journal C 80.9 (2020), p. 824. DOI: 10.1140/ epjc/s10052-020-8338-3. [4] Andrzej J. Buras et al. “K+ → π+νν ̄ and KL → π0νν ̄ in the Standard Model: status and perspectives”. In: Journal of High Energy Physics 2015.11 (2015). DOI: 10.1007/jhep11(2015)033. [5] Shoji Nagamiya. “Introduction to J-PARC”. In: Progress of Theoretical and Experimental Physics 2012.1 (Oct. 2012). 02B001. ISSN: 2050-3911. DOI: 10.1093/ptep/ pts025. [6] Masanori Ikegami. “Beam commissioning and operation of the J-PARC linac”. In: Progress of Theoretical and Experimental Physics 2012.1 (Sept. 2012). 02B002. ISSN: 2050-3911. DOI: 10.1093/ptep/pts019. [7] Hideaki Hotchi et al. “Beam commissioning and operation of the Japan Proton Accelerator Research Complex 3-GeV rapid cycling synchrotron”. In: Progress of Theoretical and Experimental Physics 2012.1 (Sept. 2012). 02B003. ISSN: 2050-3911. DOI: 10.1093/ptep/pts021. [8] Tadashi Koseki et al. “Beam commissioning and operation of the J-PARC main ring synchrotron”. In: Progress of Theoretical and Experimental Physics 2012.1 (Dec. 2012). 02B004. ISSN: 2050-3911. DOI: 10.1093/ptep/pts071. [9] Shunzo Kumano. “J-PARC Hadron Physics and Future Possibilities on Color Transparency”. In: Physics 4 (May 2022), pp. 565–577. DOI: 10.3390/physics4020037. [10] K. Takahashi H.and Agari et al. “Indirectly water-cooled production target at J-PARC hadron facility”. In: Journal of Radioanalytical and Nuclear Chemistry 305.3 (2015), pp. 803–809. ISSN: 1588-2780. DOI: 10.1007/s10967-015-3940-9. [11] T. Shimogawa. “Design of the neutral K0L beamline for the KOTO experiment”. In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 623.1 (2010). 1st International Conference on Technology and Instrumentation in Particle Physics, pp. 585–587. ISSN: 0168-9002. DOI: https://doi.org/10.1016/j.nima.2010.03.078. [12] D. Naito et al. “Development of a low-mass and high-efficiency charged-particle detector”. In: Progress of Theoretical and Experimental Physics 2016.2 (Feb. 2016). 023C01. ISSN: 2050-3911. DOI: 10.1093/ptep/ptv191. [13] Yosuke Maeda. Charged-particle veto detector for the KL → π0νν study in the J- PARC KOTO experiment. 2012. [14] Daichi Naito et al. “Evaluation of the Inefficiency of a Charged Particle Detector for the KOTO Experiment”. In: JPS Conf. Proc. 8 (2015), p. 024003. DOI: 10. 7566/JPSCP.8.024003. [15] C.Lin.“StudyofKL0 →π0νν ̄andKL0 →π0γγwiththeCluster-FindingTrigger at KOTO”. National Taiwan University, 2021. DOI: 10.6342/NTU202102308. [16] Chieh Lin. “Data-Acquisition System Upgrade for the KOTO Experiment”. In: PoS ICHEP2022 (2022), p. 242. DOI: 10.22323/1.414.0242. [17] E. Iwai et al. “Performance study of a prototype pure CsI calorimeter for the KOTO experiment”. In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 786 (2015), pp. 135–141. ISSN: 0168-9002. DOI: https://doi.org/10.1016/j.nima. 2015.02.046. [18] J. Allison et al. “Geant4 developments and applications”. In: IEEE Transactions on Nuclear Science 53.1 (2006), pp. 270–278. DOI: 10.1109/TNS.2006.869826. [19] S. Agostinelli et al. “Geant4—a simulation toolkit”. In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 506.3 (2003), pp. 250–303. ISSN: 0168-9002. DOI: https: //doi.org/10.1016/S0168-9002(03)01368-8. [20] J. Allison et al. “Recent developments in Geant4”. In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 835 (2016), pp. 186–225. ISSN: 0168-9002. DOI: https://doi. org/10.1016/j.nima.2016.06.125. [21] Kazufumi Sato. “Measurement of the CsI calorimeter performance and KL mo- mentum spectrum for the J-PARC KOTO experiment”. Ph.D. thesis. Osaka Uni- versity, 2015. [22] Particle Data Group et al. “Review of Particle Physics”. In: Progress of Theoretical and Experimental Physics 2020.8 (Aug. 2020). 083C01. ISSN: 2050-3911. DOI: 10. 1093/ptep/ptaa104. [23] Kota Nakagiri. “Search for the Decay KL0 → π0νν at the J-PARC KOTO Experiment”. Ph.D. thesis. Kyoto University, 2019. DOI: 10.14989/doctor.k21564. [24] Y. C. Tung et al. “Suppression of neutron background using deep neural network and Fourier frequency analysis at the KOTO experiment”. In: Nucl. In- strum. Meth. A 1059 (2024), p. 169010. DOI: 10.1016/j.nima.2023.169010. | - |
| dc.identifier.uri | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/94534 | - |
| dc.description.abstract | 本論文展示了在J-PARC KOTO實驗中尋找質量為零的暗光子（gamma*）於 K0 -> gamma + gamma* 衰變的研究，此研究基於2020年特殊運行數據所收集的數據。
與有質量的暗光子不同，質量為零的暗光子不會直接與普通光子混合，但可以通過直接與夸克耦合來與標準模型（SM）粒子互動。一些理論模型提出 K0 -> gamma + gamma* 衰變的分支比（BR）可能達到O(−3)。 在特殊運行中收集的K0衰變數量估計為(1.29 ± 0.02) × 1010。單一事件的靈敏度計算為(2.91 ± 0.02(stat.) ± 0.30(syst.))× 10(−8)。總背景水平的預測為(12.66 ± 4.42(stat.) ± 2.13(syst.))， 並與邊帶區域的數據相符。我們揭開了盲區並觀測到13個事件。 使用Feldman-Cousins方法計算 K0 -> gamma + gamma* 衰變的分支比上限為< 3.47 × 10(−7)(90%C.L.)。 | zh_TW |
| dc.description.abstract | This thesis presents the search for the massless dark photon (gamma*) in the K0 -> gamma + gamma* decay at the J-PARC KOTO experiment, based on the special run data collected in 2020.
Distinguished from the massive dark photon, the massless one does not directly mix with the ordinary photon but could interact with Standard Model (SM) particles through direct coupling to quarks. Some theoretical models propose that the branching ratio (BR) of the K0 -> gamma + gamma* decay could reach up to O(10−3). The number of K0 decays that had been collected in the special run is estimated to be (1.29 ± 0.02) × 1010. The single event sensitivity is calculated to be (2.91 ± 0.02(stat.) ± 0.30(syst.)) × 10−8. The total background level prediction is (12.66 ± 4.42(stat.) ± 2.13(syst.)) with the agreement from the side-band region. We uncovered the blind region and observed 13 events. The Feldman-Cousins method is used to calculate the upper limit of the K0 -> gamma + gamma* branching ratio to be < 3.47 × 10−7(90%C.L.). | en |
| dc.description.provenance | Submitted by admin ntu (admin@lib.ntu.edu.tw) on 2024-08-16T16:35:56Z No. of bitstreams: 0 | en |
| dc.description.provenance | Made available in DSpace on 2024-08-16T16:35:56Z (GMT). No. of bitstreams: 0 | en |
| dc.description.tableofcontents | Committee Approval i
Acknowledgments iii 中文摘要 v Abstract vii Contents ix List of Figures xiii List of Tables xix 1 Introduction 1 1.1 DarkMatterandDarkPhotons ........................ 1 1.2 TheoreticalPredictions............................. 2 1.3 BasicStrategyoftheKL0→γγ ̄Search .................... 2 1.3.1 SignalIdentification .......................... 3 1.3.2 MajorBackgroundSources ...................... 3 1.4 ThesisOverview ................................ 4 2 KOTO Experiment 7 2.1 J-PARCandProtonBeamline ......................... 7 2.2 KL0Beamline................................... 8 2.3 Detectors..................................... 9 2.3.1 CsI .................................... 10 2.3.2 ChargeVetoCounter.......................... 12 2.3.3 BarrelVetoCounter .......................... 12 2.4 DataAcquisitionSystem............................ 13 3 Event Reconstruction 17 3.1 PhotonClusterFinding............................. 17 3.2 Reconstructionofπ0 .............................. 19 3.3 ReconstructionofDecays ........................... 21 3.3.1 ReconstructionofKL0→3π0 ..................... 21 3.3.2 ReconstructionofKL0→γγ ̄...................... 23 3.3.3 Correction for Energy and Position of Photon Clusters . . . . . . 23 3.4 VetoHitReconstruction ............................ 24 3.4.1 BarrelVetoCounters.......................... 26 3.4.2 CsICalorimeter............................. 27 4 Monte Carlo Simulation 29 4.1 GEANT4toolkit................................. 29 4.2 DetectorResponse ............................... 30 4.3 PulseSimulation ................................ 30 4.4 KL0Generation.................................. 30 4.4.1 BeamlineSimulation.......................... 30 4.4.2 EmpiricalKL0SpectrumSimulation ................. 31 4.5 FastSimulation ................................. 32 4.6 AccidentalOverlay ............................... 34 4.7 NeutronbackgroundSimulation ....................... 34 5 KL0 Yield Estimation 37 5.1 DataSet...................................... 37 5.2 EventSelections................................. 38 5.2.1 TriggerCut ............................... 38 5.2.2 PhotonSelection ............................ 39 5.2.3 KL0Selection............................... 40 5.2.4 VetoCut................................. 43 5.3 YieldEstimation................................. 44 5.3.1 EstimationbyKL0→3π0Decays ................... 45 5.4 SummaryofKL0YieldEstimation....................... 46 6 Analysis of KL → γγ ̄ 49 6.1 DataSet...................................... 50 6.2 SingleClusterEventSelection......................... 51 6.2.1 TriggerSelection ............................ 51 6.2.2 KinematicCuts ............................. 52 6.2.3 VetoCuts ................................ 54 6.3 BackgroundSuppression............................ 56 6.3.1 KLDecayBackground......................... 56 6.3.2 NeutronBackground.......................... 59 6.4 SingleEventSensitivity............................. 64 6.4.1 SystematicUncertaintyofSES .................... 65 6.5 AdditionalBackgroundSourceStudy .................... 71 6.6 BackgroundLevelEstimation ......................... 75 6.7 UnbindtheSignalRegion ........................... 76 7 Conclusion and Discussion 79 7.1 DiscussionforNextStep............................ 80 7.2 MassiveDarkPhotonSearch.......................... 80 Bibliography 83 | - |
| dc.language.iso | en | - |
| dc.subject | 超越標準模型 | zh_TW |
| dc.subject | 無質量暗光子 | zh_TW |
| dc.subject | KOTO實驗 | zh_TW |
| dc.subject | 新物理 | zh_TW |
| dc.subject | 稀有K介子衰變 | zh_TW |
| dc.subject | rare kaon decay | en |
| dc.subject | new physics | en |
| dc.subject | KOTO Experiment | en |
| dc.subject | beyond Standard Model | en |
| dc.subject | massless dark photon | en |
| dc.title | 在KOTO實驗中尋找無質量暗光子：K0 → gamma + gamma* | zh_TW |
| dc.title | Search for a massless dark photon in K0 → gamma + gamma* at the KOTO Experiment | en |
| dc.type | Thesis | - |
| dc.date.schoolyear | 112-2 | - |
| dc.description.degree | 碩士 | - |
| dc.contributor.oralexamcommittee | 林貴林;呂榮祥;陳凱風;裴思達 | zh_TW |
| dc.contributor.oralexamcommittee | Guey-Lin Lin;Rong-Shyang Lu;Kai-Feng Chen;Stathes Paganis | en |
| dc.subject.keyword | 無質量暗光子,超越標準模型,稀有K介子衰變,新物理,KOTO實驗, | zh_TW |
| dc.subject.keyword | massless dark photon,beyond Standard Model,rare kaon decay,new physics,KOTO Experiment, | en |
| dc.relation.page | 85 | - |
| dc.identifier.doi | 10.6342/NTU202403709 | - |
| dc.rights.note | 同意授權(全球公開) | - |
| dc.date.accepted | 2024-08-14 | - |
| dc.contributor.author-college | 理學院 | - |
| dc.contributor.author-dept | 物理學系 | - |
| 顯示於系所單位： | 物理學系 | |
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