臺灣博碩士論文加值系統

中文摘要
前置量能器（EFC - Extreme Forward Calorimeter）的構想是由臺灣大學高能實驗組所提出，並成為日本國家高能加速器研究機構（KEK）的BELLE偵測器之子系統。經過三年的研發，該偵測器已於去年（１９９９）五月在日本組裝完成，並成功的運轉中。
在９８年的三月，為了EFC的製作，特將還在研發中的整組EFC帶至日本KEK進行實際的打靶測試，其經驗是在製作EFC的重要參考。
隨著BELLE的正式運轉，物理分析將是下一階段的工作重點。吾人以BELLE之GSIM電腦軟體，模擬B+ -> w pi+之衰變模式，其結果顯示應可觀察到此一衰變。

Abstract
The Extreme Forward Calorimeter (EFC) is successfully running in KEK for BELLE and she is made by the Taiwan BELLE Group. We had a beam test for the prototype EFC at KEK-PS p2 beam line by using beams with energies from 1 to 3 GeV. The prototype EFC is 1/8 of the full scale one. Due to space limitations, the BGO crystals have only 12 radiation lengths. The measured energy resolution is about 7-10% and linearity about 1%.
I also did the physics analysis in the B+ ® w p+ mode. In my study, 1973 signal events are accepted in 100,00 generated events, and 75 background events are kept in 1.92* 106 continuum events. Assuming the branching ratio of B+ -> w pi+ is 1* 105, we obtain the S/N is ~ 1.86%.

Contents
Chapter 1 Introduction----------------------------- 1
Chapter 2 BELLE and KEK-B ---------------------------- 3
2. 1 BELLE Detector --------------------------- 3
2. 1. 1 B-Factory --------------------------------- 3
2. 1. 2 Beam pipe ------------------------ 5
2. 1. 3 SVD --------------------------- 5
2. 1. 4 CDC -------------------------- 6
2. 1. 5 PID ----------------------- 7
2. 1. 5. 1 ACC ------------------------------------- 7
2. 1. 5. 2 TOF / TSC ---------------------------- 8
2. 1. 6 CsI ---------------------------- 8
2. 1. 7 MAG------------------------------------- 9
2. 1. 8 KLM ------------------------------------- 10
2. 1. 9 EFC ------------------------------------- 11
2. 2 KEK-B Accelerator ---------------------------- 14
Chapter 3 Beam Test of EFC at KEK ---------- 19
3. 1 Introduction ---------------------------- 19
3. 2 EFC Detector Part ----------------------------- 20
3. 2. 1 The Container - Test Box -------------------- 21
3. 2. 2 BGO Crystals ------------------------------ 21
3. 2. 3 Photo-diodes ------------------------------ 22
3. 2. 4 PreAmp Board ------------------------------- 23
3. 2. 5 Front End Cable ------------------------------ 25
3. 3 EFC Readout Part ----------------------------- 26
3. 2. 1 Prototype Receiver ------------------- 26
3. 3. 1. 2 MQT300A ------------------------- 28
3. 3. 2 TDC --------------------------------------- 29
3. 3. 3 The Beam --------------------------------------- 29
3. 3. 3. 1 Trigger ------------------------------ 30
Chapter 4 Spring Beam Test Result --------------------- 31
4. 1 Introduction---------------------------------------- 31
4. 2 The Data --------------------------------------- 32
4. 3 The Result --------------------------------------- 33
4. 4 The Troubles and the Solutions -------------- 36
4. 4. 1 The Pedestal ------------------------------ 36
4. 4. 2 The Test Beam Data --------------------- 36
4. 4. 3 The Test Pulse ------------------------------ 42
Chapter 5 B+ -> w pi+ Mode Physics Simulation ------- 47
5. 1 Introduction ------------------------------ 47
5. 2 The Physics About the B Meson ---------------------- 48
5. 3 Preparation of Monte Carlo (MC) Samples ---------- 49
5. 4 Event Selection ---------------------------- 50
5. 4. 1 The Beam Constrained Mass (MB) --------- 50
5. 4. 2 Energy Difference (dE) -------------------- 50
5. 4. 3 Cosine of Thrust Angle (cosqT) ---------- 51
5. 4. 4 The Second Fox-wolfram Moment (R2) ---------- 51
5. 4. 5 S^ ------------------------------------ 52
5. 4. 6 Helicity Angle --------------------------- 52
5. 5 Reconstruction of B+ Candidates ----------- 53
5. 5. 1 The Distribution of Mb and dE ---------- 53
5. 5. 2 Continuum Suppression ------------------- 54
5. 6 Summary and Discussion -------------------- 54
Chapter 6 Conclusion -------------------------------- 61

Reference
[1] M.Z. Wang, H.C. Huang, M.C. Lee, R.S. Lu, K. Ueno, C.H. Wang, W.S. Hou (1999) Beam Test of the BELLE Extreme Forward Calorimeter at KEK. BELLE Note 272.
KEK B-factory
[2] The Belle Collaboration (1997) BELLE Progress Report. High Energy
Accelerator Reseach Organization (KEK)
[3] Shin-ichi Kurokawa (1999) Status of e+e- B-factory Accelerators. BCP3 talk and http://www-acc.kek.jp/WWW-ACC-exp/KEKB/KEKB-overview/BF_HENEW.html
EFC Components
[4] LeCroy Research Systems MTQ300A (1996) Charge-to-Time Converter Specification Package.
[5] LeCroy Research Systems 1996 Catalog
B to Omega Pi
[6] CLEO Collaboration (1998) Observation of B+ -> w pi+ and the Search for Related B Decay Modes. CLNS 97/1537 CLEO 97-32
[7] Michael Gronau, Jonathan L. Rosner (1999) New Information on B Decays to Charmless VP Final States. hep-ph/9909478 v3.
trangle garma
[8] Michael Gronau, Jonathan L. Rosner (1999) New Information on B Decays to Charmess VP Final States. TECHNION-PH-99-33 EFI-99-40 hep-ph/9909478
[9] Stanley M. Flatté, Darrelle O. Huwe, Joseph J. Murray, Janice Button-Shafer, Frank T. Solmitz, M. Lynn Stevenson, and Charles Wohl (1965) Decay Properties of w Meson. Physics Review vol. 145, Number 4, 1050-1061
[10] G. Kramer, W.F. Palmer (1992) Polarization and CP asymmetries in the decay B -> K* y, K* w, and K* r. Physics Letters B 279 (1992) 181-188
[11] Jesse Abram Ernst (1995) First Measurement of the Rate for the Inclusive Radiative Penguin Decay b -> sg. PHD Thesis, University of Rochester.
[12] Sheldon Stone (Editor, 1994) B Decays. World Scientific.
[13] Kyung Kwang Joo (1998) Simulation Study of Rare Decay B+ -> w K+. BELLE Note #247.