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)是对基本粒子物理定律的准确描述，但它留下了许多问题没有得到回答。这些问题与暗物质的性质、宇宙中缺乏反物质以及已知力量可能的统一有关。解决这些谜团需要将我们目前对看似互不关联的理论的理解合并到一个单一的框架中，称为万物理论(TOE)。大多数对撞机实验都没有产生与SM的偏差，这将为导致脚趾的新模型提供支持。在过去和现在的实验中，有一个与SM明显背离的地方，有可能解决未回答的问题。SM指出，不同的轻子家族的行为相似。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，这些观测结果可能是SM以外的新物理学造成的。主要的理论解释是轻夸克的存在。轻夸克是由Beyond SM理论预测的，该理论旨在将我们目前的知识统一到一个单一的万物理论中。我建议进行第一次专门的ATLAS搜索，寻找衰变到顶级夸克和tau轻子的轻夸克。顶部粒子和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，这对测量这些最终状态至关重要。阿特拉斯将于2019年升级，以跟上日益苛刻的大型强子对撞机(LHC)运行条件。升级包括增加一个跟踪系统(Fast Tracker-FTK)，改进电磁量热计，以及增加被称为新小轮(New Small Wheel)的介子室。在FTK工作过后，我计划如何改进b夸克和tau轻子的测量。我还建议通过为电磁量热计和新南威尔士州安装和调试一个名为Felix的读出系统，专注于电子和Muon的改进。作为在ATLAS中安装和集成复杂电子系统的专家之一，我可以确保Felix读数的成功安装。该Felix项目是加拿大ATLAS硬件项目的补充，因为它将用于读出电磁量热计、新南威尔士州和内跟踪器(ITK)，所有这些都是加拿大的大规模努力。