Experimental Study of Heavy Flavor and CP Violation with the LHCb Experiment at the CERN LHC Collider

在 CERN LHC 对撞机上使用 LHCb 实验进行重味和 CP 破坏的实验研究

• 批准号: 1907466
• 负责人: Abolhassan Jawahery
• 金额: $ 32.5万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2022-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1907466&HistoricalAwards=false
• 关键词: Experimental; Study; Heavy; Flavor; CP

One of the major intellectual achievements of the 20th century was the development of the Standard Model (SM) of particle physics. This model succeeded in classifying all of the elementary particles known at the time into a hierarchy of groups having similar quantum properties. The validity of this model to date was confirmed by the discovery of the Higgs boson at the Large Hadron Collider at CERN. However, the Standard Model as it currently exists, leaves open many questions about the universe. These include why matter dominates over anti-matter in the Universe (CP violation), the values of the masses of the fundamental constituents, the quarks and the leptons, the size of the mixings among the quarks, and separately among the leptons, and the properties of dark matter. Most explanations require the presence of new particles, symmetries or forces, which we call Beyond the Standard Model Physics (BSM). This project is designed to pursue searches for BSM physics. The LHC is the premier High Energy Physics particle accelerator in the world and is currently operating at the CERN laboratory near Geneva Switzerland, one of the foremost facilities for answering these BSM questions. The Maryland group is a collaboration member of LHCb, an experiment designed specifically to study the decays of hadrons containing b or c quarks at the LHC. The goal of LHCb is to identify new physics in nature by examining the properties of hadrons containing these quarks. New physics, or new forces, can be manifest by particles, as yet to be discovered, whose presence would modify decay rates and CP violating asymmetries of hadrons containing the b and c quarks, and thus allow new phenomena to be observed indirectly. Analytically, the Maryland program is focused on measurements related to two of the current anomalies in the decays of B mesons: hints of departure from Lepton Flavor Universality in semi-leptonic B decays and the long-standing so-called K-pi puzzle where the measured CP asymmetries in the family of B decays into the K-pi final state deviate from the expected simple predictions. These anomalies, if confirmed, could be due to the imprints of BSM physics. Technically, the Maryland group leads the development and construction of the off-detector electronics for the new upstream tracker (UT) in the LHCb upgrade and participation in the installation and commissioning of the tracker. The UT represents a major US contribution to the upgrade of the experiment to improve event reconstruction overall and particularly for rare events of the type under study by the Maryland team.The group works closely with an outreach program run by the physics and astronomy departments at the University of Maryland, called GRAD-MAP, which is aimed at providing research and training opportunities for undergraduates from underrepresented groups in the Maryland and Washington area community colleges. The LHCb experiment, with its technical challenges and exciting physics program, serves as a major attractor for student participation.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

20世纪的主要知识成就之一是粒子物理学标准模型（SM）的发展。该模型成功地将当时已知的所有基本粒子分类为具有相似量子特性的组的层次结构。迄今为止，通过发现Higgs玻色子在CERN的大型强子对撞机上发现了该模型的有效性。但是，目前存在的标准模型留下了有关宇宙的许多问题。其中包括为什么物质在宇宙中占主导地位（违反CP），基本成分质量的值，夸克和叶子的质量，夸克之间的混合大小以及卵子中的混合大小，在lept子中分别以及暗物质的性质。大多数解释都需要存在新的粒子，对称性或力，我们将其称为标准模型物理（BSM）。该项目旨在追求BSM物理学的搜索。 LHC是世界上首要的高能物理粒子加速器，目前在瑞士日内瓦附近的CERN实验室运营，这是回答这些BSM问题的最重要设施之一。马里兰州集团（Maryland Group）是LHCB的合作成员，该实验专门研究LHC上包含B或C夸克的Hadron的衰变。 LHCB的目的是通过检查包含这些夸克的Hadron的特性来识别自然界的新物理学。新的物理学或新力可以通过颗粒表现出来，尚待发现，其存在会改变腐烂的速率和违反包含B和C夸克的Hadron的CP，因此可以间接观察到新现象。 Analytically, the Maryland program is focused on measurements related to two of the current anomalies in the decays of B mesons: hints of departure from Lepton Flavor Universality in semi-leptonic B decays and the long-standing so-called K-pi puzzle where the measured CP asymmetries in the family of B decays into the K-pi final state deviate from the expected simple predictions.如果确认这些异常可能是由于BSM物理学的烙印所致。从技术上讲，马里兰州集团在LHCB升级中的新上游跟踪器（UT）领导和构建了探索器电子设备的开发和建设，并参与了跟踪器的安装和调试。 UT代表了美国对实验升级的主要贡献，以改善整体的事件重建，尤其是对于马里兰州团队所研究类型的罕见事件。该小组与马里兰州大学的物理和天文学系进行的外展计划紧密合作，称为Grad-Map，称为Grad Map，旨在为玛丽群体提供少年的培训，旨在为玛丽提供培训，并在玛丽群岛上提供培训，并培训了玛丽的班级，并在玛丽·米尔兰（Marryselland）的范围内，并在玛丽·米尔兰（Marryselland）的工作中，并在玛丽（Marryselland）的范围内，并在玛丽（Mary）的范围内培养了培训。 LHCB实验凭借其技术挑战和令人兴奋的物理计划是学生参与的主要吸引者。该奖项反映了NSF的法定任务，并使用基金会的知识分子优点和更广泛的影响审查标准，被认为值得通过评估来获得支持。