跳到主要內容

臺灣博碩士論文加值系統

(44.192.20.240) 您好!臺灣時間:2024/02/24 02:20
字體大小: 字級放大   字級縮小   預設字形  
回查詢結果 :::

詳目顯示

我願授權國圖
: 
twitterline
研究生:盧沛成
研究生(外文):Pei-Cheng Lu
論文名稱:B介子衰變至η K π之Dalitz分析
論文名稱(外文):Dalitz Analysis of Three-body Charmless Hadronic decay B to η K π
指導教授:王名儒
指導教授(外文):Win-Zu Wang
口試委員:張寶棣王正祥徐靜戈
口試委員(外文):Pao-Ti ChangChung-Hsiang WangJing-Ge Shiu
口試日期:2014-06-13
學位類別:碩士
校院名稱:國立臺灣大學
系所名稱:物理研究所
學門:自然科學學門
學類:物理學類
論文種類:學術論文
論文出版年:2014
畢業學年度:102
語文別:英文
論文頁數:138
中文關鍵詞:B介子貝爾實驗三體衰變稀有衰變Dalitz分析
外文關鍵詞:B mesonBelleThree-body decayRare decayDalitz plot analysis
相關次數:
  • 被引用被引用:0
  • 點閱點閱:330
  • 評分評分:
  • 下載下載:0
  • 收藏至我的研究室書目清單書目收藏:0
我們使用了日本筑波KEK之B工廠於1998至2010年間收集之771.581百萬BBbar介子對實驗數據。我們量測了B0衰變至η K+ π-三體末態的CP對稱破壞以及各中間態之衰變分支比,藉由Dalitz分析,能夠更清楚完整地了解此衰變的結構。此量測不考慮魅夸克中間態,只聚焦於底夸克至奇夸克的轉換,亦即稀有衰變的部分。至於η的衰變末態,我們只考慮了η → γγ 和 η → π+π-π0。

考慮所有中間態,在η → γγ此分支中,我們量測到的CP對稱破壞為-0.049^{+0.053}_{-0.052}+-0.046,在η → π+π-π0分支則為0.220^{+0.088}_{-0.084}+-0.040$,第一個誤差為統計誤差,第二個則是系統誤差。各中間態的衰變分支比量測結果可在此論文中見到。

We are going to determine the CP asymmetries and to measure branching fractions by Dalitz analysis for the three-body charmless hadronic B decay: B0 → η K+ π-; the branches η → γγ and η → π+π-π0 are considered. This work is based on a data sample of 771.581 million BBbar pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric energy
electron-positron collider.

The measured branching fraction for all intermediate states are reported, we also measured Acp of inclusive charmless decay B0 → η(γγ) K+ π- = -0.049^{+0.053}_{-0.052}+-0.046 and that of B0 → η(π+π-π0) K+ π- = $0.220^{+0.088}_{-0.084}+-0.040$, the first error is statistical error and the second one is systematic error.

1 Introduction 1
1.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Standard Model . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2.1 Mesons . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2.2 Exotic Mesons . . . . . . . . . . . . . . . . . . . . . . . 5
1.2.3 B Physics . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.2.4 The Cabibbo-Kobayashi-Maskawa Matrix . . . . . . . . . 8
1.2.5 CP violation . . . . . . . . . . . . . . . . . . . . . . . . 9
1.3 Dalitz plot analysis . . . . . . . . . . . . . . . . . . . . . . . . . 11
2 Belle Experiment 13
2.1 KEKB B-Factory . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.2 BELLE Detector . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.2.1 Beam-line Magnets near the IP and Beam Pipe . . . . . . 17
2.2.2 Extreme Forward Calorimeter (EFC) . . . . . . . . . . . 21
2.2.3 Silicon Vertex Detector (SVD) . . . . . . . . . . . . . . . 22
2.2.4 Central Drift Chamber (CDC) . . . . . . . . . . . . . . . 24
2.2.5 Aerogel &;#268;erenkov Counter System (ACC) . . . . . . . . . 25
2.2.6 Time-of-Flight Counters (TOF) . . . . . . . . . . . . . . 28
2.2.7 Electromagnetic Calorimeter (ECL) . . . . . . . . . . . . 29
2.2.8 Particle Identification of Electrons and Charged Kaons,
EID and KID . . . . . . . . . . . . . . . . . . . . . . . . 31
2.2.9 KL and Muon Detection System (KLM) . . . . . . . . . . 32
3 B Reconstruction and Event Selection 35
3.1 Charged Particle Selection . . . . . . . . . . . . . . . . . . . . . 35
3.2 η Reconstruction . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.3 Best Candidate Selection . . . . . . . . . . . . . . . . . . . . . . 38
3.4 The Modified Mbc . . . . . . . . . . . . . . . . . . . . . . . . . . 39
3.5 Selections Summary . . . . . . . . . . . . . . . . . . . . . . . . 40
4 Background Study 45
4.1 Overview of Backgrounds Study . . . . . . . . . . . . . . . . . . 45
4.2 Continuum Background . . . . . . . . . . . . . . . . . . . . . . . 45
4.2.1 ΔZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
4.2.2 cosθB . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
4.2.3 Kakuno Super Fox-Wolfram(KSFW) . . . . . . . . . . . 46
4.2.4 Fisher Discriminant . . . . . . . . . . . . . . . . . . . . . 48
4.2.5 Likelihood Ratio(LR) . . . . . . . . . . . . . . . . . . . . 50
4.2.6 Optimization of LR cut . . . . . . . . . . . . . . . . . . . 50
4.3 Generic B Background . . . . . . . . . . . . . . . . . . . . . . . 52
4.4 Rare B Background . . . . . . . . . . . . . . . . . . . . . . . . . 52
4.5 Feedacross Background . . . . . . . . . . . . . . . . . . . . . . . 54
5 Control Sample Study 57
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
5.2 Fitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
5.3 Calibration Factor Results . . . . . . . . . . . . . . . . . . . . . 61
5.4 η Selection Check . . . . . . . . . . . . . . . . . . . . . . . . . . 65
6 Amplitude Analysis on Dalitz Plot 69
6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
6.2 Three-Body Signal Yields . . . . . . . . . . . . . . . . . . . . . . 69
6.3 Signal Amplitude Formalism . . . . . . . . . . . . . . . . . . . . 75
6.3.1 LASS Parametrization . . . . . . . . . . . . . . . . . . . 77
6.4 Efficiency over Dalitz Plot and Smearing . . . . . . . . . . . . . 78
6.5 Sideband Background Modeling . . . . . . . . . . . . . . . . . . 81
6.6 Dalitz Plot Boundary . . . . . . . . . . . . . . . . . . . . . . . . 83
6.7 Fitting and Goodness-of-Fit . . . . . . . . . . . . . . . . . . . . . 84
6.8 Fit Strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
7 Systematics and Efficiency Correction 87
7.1 Tracking uncertainty . . . . . . . . . . . . . . . . . . . . . . . . 87
7.2 PID Identification Uncertainty . . . . . . . . . . . . . . . . . . . 87
7.3 Number of B ¯B pairs uncertainty . . . . . . . . . . . . . . . . . . 89
7.4 Signal PDF(ΔE, Mbc) uncertainty . . . . . . . . . . . . . . . . . 89
7.5 Rare B PDF uncertainty . . . . . . . . . . . . . . . . . . . . . . . 89
7.6 MC efficiency uncertainty . . . . . . . . . . . . . . . . . . . . . 90
7.7 η efficiency correction and systematics . . . . . . . . . . . . . . . 90
7.8 π0 efficiency and systematic error . . . . . . . . . . . . . . . . . 90
7.9 LR cut uncertainty . . . . . . . . . . . . . . . . . . . . . . . . . 91
7.10 Reconstruction Efficiency . . . . . . . . . . . . . . . . . . . . . 91
8 Summary and Conclusion 95
8.1 Fitting Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
8.2 Floating Background . . . . . . . . . . . . . . . . . . . . . . . . 106
8.3 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
8.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
A Bias of 2D (ΔE, Mbc) fit 109
B Bias of Dalitz fitter 111
C Figures of Dalitz Plot Sideband Modeling 121
D Dalitz analysis Backup 127
E Results of Inclusive Decay 133

[1] "Standard Model of Elementary Particles" (Wikipedia), http:
//en.wikipedia.org/wiki/File:Standard_Model_of_Elementary_
Particles.svg/.
[2] "Elementary Particle Interactions." (Wikipedia), http://en.wikipedia.
org/wiki/File:Elementary_particle_interactions.svg.
[3] "The Upsilon System", http://www.lns.cornell.edu/public/
lab-info/upsilon.html.
[4] "CP violation" (Wikipedia), http://en.wikipedia.org/wiki/CP_
violation.
[5] A. Abashian et al., "The Belle Detector", Nucl. Instrum Methods Phys. Res.
Sect. A 479, 1, 117--232 (2002).
[6] "Belle SVD 2 Upgrade Technical Design Report Version 3.1" (2001).
[7] J. Beringer et al., "Review of Particle Physics", Phys. Rev. D 86, 010001
(2012).
[8] S. Kurokawa and E. Kikutani, "Overview of the KEKB Accelerators", Nucl.
Instrum. Methods Phys. Res. Sect A 499, 1, 1--7 (2003).
[9] A. Garmash et al., "Dalitz analysis of the three-body charmless decaysB+ !
K+π+π&;#8722; and B+ ! K+K+K&;#8722;", Phys. Rev. D 69, 012001 (2004).
[10] Bernard Aubert et al., "Measurement of branching fractions and charge
asymmetries in B decays to an eta meson and a K* meson", Phys.Rev.Lett.
97, 201802 (2006).
[11] C.H. Wang et al., "Measurement of charmless B Decays to eta K* and eta
rho", Phys.Rev. D 75, 092005 (2007).
[12] B. Martin and G. Shaw, Particle Physics, Manchester Physics Series. Wiley
(2008), ISBN 9780470721537.
[13] "Standard Model" (Wikipedia), http://en.wikipedia.org/wiki/
Standard_Model.
[14] Nobel Prize Organization, http://www.nobelprize.org/.
[15] R. L. Jaffe, , Phys. Rev. D 15, 267, 281 (1997).
[16] S. W. Herb et al., "Observation of a Dimuon Resonance at 9.5 GeV in 400-
GeV Proton-Nucleus Collisions", Phys. Rev. Lett. 39, 252--255 (1977).
[17] T. E. Browder and K. Honscheid, "B Mesons", Prog. Part. Nucl. Phys. 35,
0, 81--219 (1995).
[18] N. Cabibbo, "Unitary Symmetry and Leptonic Decays", Phys. Rev. Lett. 10,
531 (1963).
[19] M. Kobayashi and T. Maskawa, "CP-Violation in the Renormalizable Theory
of Weak Interaction", Prog. Theor. Phys. 49, 2, 652--657 (1973).
[20] L. L. Chau and W. Y. Keung, "Comments on the Parametrization of the
Kobayashi-Maskawa Matrix", Phys. Rev. Lett. 53, 1802 (1984).
[21] L. Wolfenstein, "Parametrization of the Kobayashi-Maskawa Matrix", Phys.
Rev. Lett. 51, 1945--1947 (1983).
[22] V. L. Fitch J. H. Christenson, J. W. Cronin and R. Turlay, "Evidence for the
2π Decay of the K0
2 Meson", Pisma Zh. Eksp. Teor. Fiz. 5, 32--35 (1967).
[23] A. B. Carter and A. I. Sanda., "CP Nonconservation in Cascade Decays of
B Mesons", Phys. Rev. Lett. 45, 952--954 (1980).
[24] K. Abe et al., "Observation of Large CP Violation in the Neutral B Meson
System", Phys. Rev. Lett. 87, 091802 (2001).
[25] M. Kobayashi and T. Maskawa, "CP-violation in the Renomalizable Theory
of Weak Interaction", Progress of Theoretical Physics 49, 2, 652--657 (1973).
[26] "KEKB B-Factory Design Report", 95-7 (1995).
[27] "Belle Progress Report" (March, 1997).
[28] K. Ueno et al., "Proceedings of the Calorimetry Conference" (1999).
[29] M. Z. Wang et al., ``Review of EFC options'', Belle Note 164 (1996).
[30] K. Ueno et al., "Detection of minimum-ionizing particles and nuclear counter
effect with pure BGO and BSO crystals with photodiode readout", Nucl.
Instr. and Meth. A396, 103 (1997).
[31] M. Z. Wang et al., "Beam test of the BELLE extreme forward calorimeter at
KEK", Nucl. Instr. and Meth. A455, 319 (2000).
[32] Y. Ushiroda et al., "Belle silicon vertex detectors", Nucl. Instr. and Meth.
A511, 6--10 (2003).
[33] Z. Natkaniec et al., "Belle SVD2 Vertex Detector", Nucl. Instrum. Methods
Phys. Res. Sect. A568, 269--273 (2006).
[34] S. Uno, "The BELLE central drift chamber", Nucl. Instr. and Meth. A379,
421--423 (1996).
[35] H. Hirano et al., "A high-resolution cylindrical drift chamber for the KEK
B-factory", Nucl. Instr. and Meth. A455, 294--304 (2000).
[36] S. Uno et al., "Study of a drift chamber filled with a helium-ethane mixture",
Nucl. Instr. and Meth. A330, 55--63 (1993).
[37] O. Nitoh et al., "Drift Velocity of Electrons in Helium-Based Gas Mixtures
Measured with a UV Laser", Jan. J. Appl. Phys. 33, 5929 (1994).
[38] I. Adachi et al., "Study of a threshold Cherenkov counter based on silica
aerogels with low refractive indices", Nucl. Instr. and Meth. A355, 390--398
(1995).
[39] "Belle Technical Design Report", KEK Report 95-1 (1995).
[40] K. Hanagaki et al., "Electron Identification in Belle", Nucl. Instrum. Methods
Phys. Res. Sect. A485, 3, 490--503 (2002).
[41] S.J. Richichi et al., "Two-body B meson decays to eta and eta-prime: Observation
of B to eta K*", Phys.Rev.Lett. 85, 520--524 (2000).
[42] M. Wirbel et al., "Exclusive Semileptonic Decays of Heavy Mesons, Zeit.
Phys. C29, 637 (1985).
[43] Particle Data Group, http://pdglive.lbl.gov/.
[44] A.Wuethrich, "Dalitz Plots and Hadron Spectroscopy", hep-ph/0207058v1
page 28 (2005).
[45] B. Bhuyan, "High PT Tracking Efficiency Using Partially Reconstructed D&;#8727;
Decays (Belle internal)", Belle Note 1165 (2010).
[46] "Number of B in HadronB(J)" (Belle internal), http://belle.kek.jp
secured/nbb/nbb.html.

QRCODE
 
 
 
 
 
                                                                                                                                                                                                                                                                                                                                                                                                               
第一頁 上一頁 下一頁 最後一頁 top
無相關期刊