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: $ 9.47万
• 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: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=739457
• 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.

尽管标准模型（SM）准确地描述了基本粒子物理定律，但它留下了许多悬而未决的问题。这些问题与暗物质的性质、宇宙中反物质的缺乏以及已知力的可能统一有关。解决这些谜团需要将我们目前对看似互不相关的理论的理解合并到一个单一的框架中，即万有理论（ToE）。大多数对撞机实验并未产生与 SM 的偏差，这将为导致 ToE 的新模型提供支持。在过去和现在的实验中发现，SM 存在一个显着的偏差，有可能解决尚未解答的问题。 SM 指出不同轻子家族的行为相似。然而，Belle、BaBar 和 LHCb 实验进行的多项测量表明情况可能并非如此。这些结果有 1/15 000 的概率是由于数据的统计波动造成的。这表明SM之外的新物理学可能对这些观测结果负责。 主要的理论解释是轻夸克的存在。轻夸克是由超越 SM 理论预测的，该理论旨在将我们当前的知识统一到一个单一的万物理论中。我建议对衰变为顶夸克和 tau 轻子的轻夸克进行第一次专门的 ATLAS 搜索。顶粒子和 tau 粒子衰变为 b 夸克、电子/μ 子与中微子和较轻夸克的各种组合。我对包含这些最终状态的许多分析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 将于 2019 年进行升级，以满足日益严格的大型强子对撞机 (LHC) 运行条件。升级包括增加跟踪系统（Fast TracKer - FTK）、改进电磁量热计以及额外的μ子室（称为新小轮（NSW））。在完成 FTK 工作后，我计划如何改进 b 夸克和 tau 轻子测量。我进一步建议通过为电磁量热计和 NSW 安装和调试名为 FELIX 的读出系统来重点关注电子和 μ 子的改进。作为将复杂电子系统安装和集成到 ATLAS 的专家之一，我可以确保 FELIX 读数器的成功安装。该 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热量计、NSW 和 Inner TracKer (ITK)，所有这些都是加拿大的大规模工作。