ATLAS Bridging Application: Are Leptoquarks the Ultimate Answer?

ATLAS 桥接应用：轻夸克是最终答案吗？

• 批准号: SAPPJ-2019-00048
• 负责人: Ilic, Nikolina
• 金额: $ 8.6万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Project
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=693036
• 关键词: ATLAS; Bridging; Application; Leptoquarks; Ultimate

Although the Standard Model (SM) is an accurate description of the fundamental particle physics laws, it leaves many questions unanswered. These questions are related to the nature of dark matter, the lack of anti-matter in the universe, and the possible unification of the known forces. Addressing these mysteries requires merging our current understanding of seemingly disconnected theories into a single framework, known as the Theory of Everything (ToE). Most collider experiments have not yielded deviations from the SM, which would provide support of new models that lead to a ToE.******There is one prominent deviation from the SM seen in past and present experiments that has the potential to address unanswered questions. The SM states that the different families of leptons behave similarly. However, several measurements performed by the Belle, BaBar and LHCb experiments indicate that this might not be the case. There is a 1/15 000 probability that these results are due to a statistical fluctuation in the data. This suggests the possibility that new physics beyond the SM is responsible for these observations. ******The leading theoretical explanation is the existence of Leptoquarks. Leptoquarks are predicted by beyond SM theories which aim to unify our current knowledge into a single Theory of Everything. I propose to perform the first dedicated ATLAS search for Leptoquarks decaying to top quarks and tau leptons. The top and tau particles decay to various combinations of b-quarks, electrons/muons with neutrinos and lighter quarks. My work on many analyses containing these final states have provided me with unique expertise to perform this search.******In addition, I propose to work on upgrades to the ATLAS detector that are critical for the measurement of these final states. ATLAS will be upgraded in 2019 in order to keep up with increasingly demanding Large Hadron Collider (LHC) operating conditions. The upgrades include the addition of a tracking system (Fast TracKer - FTK), improvements to the electromagnetic calorimeter, and additional muon chambers, called the New Small Wheel (NSW). Having worked on the FTK, I have plans on how to improve b-quark and tau lepton measurements. I further propose to focus on the electron and muon improvements by installing and commissioning a readout system, called FELIX, for the electromagnetic calorimeter and NSW. As one of the experts in the installation and integration of complicated electronics systems into ATLAS, I can ensure the successful installation of the FELIX readout. This FELIX project is complimentary to Canadian ATLAS hardware projects, since it will be used to readout the electromagnetic calorimeter, NSW and Inner TracKer (ITK), all of which are large scale Canadian efforts.*****

虽然标准模型（SM）是对基本粒子物理定律的准确描述，但它留下了许多未解之谜。这些问题与暗物质的本质、宇宙中反物质的缺乏以及已知力的可能统一有关。要解决这些谜团，我们需要将目前对看似不相关的理论的理解整合到一个单一的框架中，即所谓的万物理论（ToE）。大多数对撞机实验都没有产生偏离SM的结果，这将为导致ToE的新模型提供支持。******在过去和现在的实验中，有一个明显的偏离SM的地方，它有可能解决未回答的问题。SM指出不同的轻子族的行为是相似的。然而，Belle、BaBar和LHCb实验进行的几项测量表明，情况可能并非如此。这些结果有1/ 15000的概率是由于数据中的统计波动造成的。这表明有可能是SM之外的新物理学导致了这些观测结果。******最主要的理论解释是轻夸克的存在。轻夸克是由SM理论预测的，SM理论旨在将我们目前的知识统一为一个单一的万有理论。我建议进行第一次专门的ATLAS搜索，寻找衰变为顶夸克和tau轻子的轻夸克。顶粒子和τ粒子衰变为b夸克、电子/ μ子、中微子和较轻的夸克的各种组合。我在许多包含这些最终状态的分析方面的工作为我提供了执行此搜索的独特专业知识。******此外，我建议对ATLAS探测器进行升级，这对于测量这些最终状态至关重要。ATLAS将在2019年进行升级，以跟上要求越来越高的大型强子对撞机（LHC）的运行条件。升级包括增加跟踪系统（Fast TracKer - FTK），改进电磁量热计和额外的介子室，称为新小轮（NSW）。在研究了FTK之后，我计划如何改进b夸克和tau轻子的测量。我进一步建议通过为电磁量热计和NSW安装和调试一个名为FELIX的读出系统来关注电子和介子的改进。作为ATLAS安装和集成复杂电子系统的专家之一，我可以确保FELIX读出器的成功安装。这个FELIX项目是对加拿大ATLAS硬件项目的补充，因为它将用于读取电磁量热计，NSW和内部跟踪器（ITK），所有这些都是加拿大的大规模努力。*****