尋找D0 -> nu nu-bar以及B0 -> p Lambda-bar pi- gamma衰變,與BelleII中央飄移室觸發系統之韌體設計

本論文主要包含三個主題。第一、二部分為以KEKB對撞機於Belle偵測器累積的數據進行物理分析。第三部分為Belle II中央飄移室觸發系統的韌體設計。第一個主題為尋找D0至不可見末態粒子以及測量D0 -> h- l+ nu衰變，數據來源是Belle偵測器收集於KEKB對撞機於接近Y(4S)與Y(5S)震盪態產生的事件，這些衰變模式的絕對分支比可藉由魅夸克味標籤法所得到，在D0至不可見末態粒子的測量結果中沒有發現顯著性的訊號，因此我們以90%的信心水準，設定此衰變的分支比上限為8.8*10^(-5)。我們也用相同的分析方法測量了四個D0 -> h- l+ nu的衰變分支比，其測量結果與PDG的世界平均值相合。第二個主題為尋找B0 -> p Lambda-bar pi- gamma之衰變，在理論預測中，此模式主要透過b -> s gamma的途徑衰變，於末態包含一個高能量的光子，測量結果中沒有發現顯著性的訊號，因此我們以90%的信心水準，設定此衰變的分支比上限為6.5*10^(-7)。第三個主題是台大高能實驗室參與Belle II第一階中央飄移室觸發系統的研究，在此系統中，Merger電路板負責簡化從前端讀出板的資料，再傳送到後段的帶電粒子軌跡重建模組，關於Merger電路板各方面的設計將在論文中詳細描述。台大團隊發展了自定義的光纖傳輸通訊協定，使用於在中央飄移室觸發系統的資料流之中，亦發展了整體系統的流量控制與資料同步的方式，論文中也會提到此通訊協定的發展與應用的細節。

關鍵字

夸克味標籤；暗物質；輻射性B介子衰變；強子性B介子衰變；觸發系統； FPGA韌體；光纖傳輸

並列摘要

The thesis includes three major topics. Two physics data analysis on D0 and B0 decays at Belle. The other is the firmware design for Belle II CDCTRG system. The first topic is a search for the D0 -> nu nu-bar decay at Belle. We study the D0 decay to nu nu-bar and h- l+ nu (h=K,pi, and l=e,mu) using the data sample collected at or near the Y(4S) and Y(5S) with Belle detector at the KEKB asymmetric energy e+e- collider. Absolute branching fraction measurements of these decays are done with charm flavor tagging method. Since no significant signal is found, we set an upper limit of 8.8*10^(-5) for the branching fraction of D0 -> nu nu-bar at the 90% confidence level. We also perform the measurement of D0 -> h- l+ nu, and the measured branching fractions are consistent with the PDG world average. The second topic is the search for the charmless B0 decay with final state particles p Lambda-bar pi- gamma. This decay is predicted to proceed predominantly via the b -> s gamma radiative penguin process with a high energy photon. No significant signal is found. We set an upper limit of 6.5*10^(-7) for the branching fraction of B0 -> p Lambda-bar pi- gamma at the 90% confidence level. The third topic is NTUHEP group's work on Belle II Level-1 CDCTRG system. In this system, the trigger Merger boards simplify the data flow from readout boards to the rear-end tracking modules. The development of Merger, including hardware and firmware, will be presented in this thesis. For the data flow in the CDCTRG system, we developed an user-defined optical transmission protocol, and also the scheme of data flow control and synchronization for the whole trigger system. The design of user-defined protocol and its application will also be introduced.

並列關鍵字

Quark flavor tagging ； Dark Matter ； Radiative B decay ； Baryonic B decay ； Trigger system ； FPGA firmware ； Optical transmission

參考文獻

[1] M. Herrero, "The Standard Model", arXiv:hep-ph/9812242.

[2] "Standard Model of Elementary Particles" (Wikipedia), http://en.wikipedia.org/wiki/File:Standard_Model_of_Elementary_Particles.svg.

[4] N. Cabibbo, "Unitary Symmetry and Leptonic Decays", Phys. Rev. Lett. 10, 531-533 (1963).

[5] M. Kobayashi and T. Maskawa, "CP-Violation in the Renormalizable Theory of Weak Interaction", Progress of Theoretical Physics 49, 2, 652-657 (1973).

[6] L. L Chau and W. Y. Keung, "Comments on the Parametrization of the Kobayashi-Maskawa Matrix", Phys. Rev. Lett. 53, 1802-1805 (1984).

國際替代計量

尋找D0 -> nu nu-bar以及B0 -> p Lambda-bar pi- gamma衰變,與BelleII中央飄移室觸發系統之韌體設計

全文下載

主題瀏覽