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: 2309144
• 负责人: Abolhassan Jawahery
• 金额: $ 135万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2309144&HistoricalAwards=false
• 关键词: Experimental; Study; Heavy; Flavor; CP

One of the greatest scientific achievements of the past century has been the development of the Standard Model of elementary particles, the quarks and leptons, and their interactions. The precise tests of the fundamental elements of the Standard Model are among the most important goals of the continuing research in elementary particle physics. This project focuses on an experimental study of heavy flavor, which refers to the studies of the particles containing the charm (c) and the bottom (b) quarks, and CP violation, the differences in the properties of the particles and their antiparticles counterpart. The studies, which will be conducted with the LHCb experiment at the Large Hadron Collider at CERN, include precise tests of the mechanism responsible for the differences in the properties of matter and antimatter as well as examination of the universal behavior of charged leptons, a cornerstone of the Standard Model. The findings of the flavor physics, in particular a potential discovery of new sources of CP violation beyond the Standard Model, will also likely have a profound impact on the understanding of the origin of the matter-antimatter asymmetry in the universe and the field of cosmology. Experimental particle physics also serves as an extremely rich environment for training students at all levels, as well as postdoctoral researchers and engineers at the leading edge of a diverse range of technologies. The Maryland group has had strong record in this area, enabled by the development of the first upgrade of the LHCb detector, and aims to continue and strengthen this program with the next major improvement plan of the detector in the coming decade.The proposed program includes the completion of the commissioning of the upstream tracker in the LHCb upgrade, whose construction has been a key focus of the group, as well as a major participation in the physics analysis of the data recorded by LHCb in Runs 1 & 2 and the anticipated data from the operation of the experiment in the next three years, Run 3. The physics studies program is focused on measurements related to two of the current anomalies in the decays of B mesons: (1) hints of departure from Lepton Flavor Universality in semileptonic B decays and (2) studies of CP violation in the family of B → Kπ decays, where the current measurements of the CP asymmetries deviate from the expected pattern based on isospin symmetry- the long standing so-called ”Kπ” puzzle. These anomalies, if confirmed, could be due to the presence of new physics effects in flavor processes. The program also includes major participation in the development of the next major upgrade of the LHCb detector- Upgrade II, which is expected to lead to significant improvement in the precision of flavor processes. At the current level of precision, measurements of the key flavor observables, currently largely consistent with the Standard Model predictions, impose severe constraints on the energy scale and the structure of new physics models. However, areas of deviations from the SM are emerging, such as signs of lepton non-universality in semileptonic B decays, which are highly sensitive to the presence of new scalars. The precision of future measurements in some key areas, based on the data from LHCb and its upgraded detector, are expected to reach the required sensitivity to clarify some of these anomalies or further strengthen the deviations from the SM predictions. These results could, in conjunction with studies at the energy frontier, point the way to the structure of the physics beyond the SM.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.

过去一个世纪的最大科学成就之一是开发了基本颗粒，夸克和叶子及其相互作用的标准模型。标准模型的基本要素的精确测试是基础粒子物理中持续研究的最重要目标之一。该项目的重点是对浓风味的实验研究，该研究指的是含有魅力（C）和底部（B）夸克的颗粒的研究，以及违反CP的研究，颗粒及其反粒子的性质差异。这些研究将通过CERN的大型强子对撞机的LHCB实验进行，包括对负责物质和反物质性质差异的机制的精确测试，以及对带电leptons的普遍行为的检查，这是标准模型的基础。风味物理学的发现，特别是在标准模型之外的新来源违规来源的潜在发现，也可能会对对宇宙中物质抗逆性不对称起源的理解和宇宙学领域产生深远的影响。实验性粒子物理学也是一个非常丰富的环境，可用于各个级别的学生，以及潜水员技术范围的前沿的博士后研究人员和工程师。马里兰州小组在该领域的记录很强，这是通过开发LHCB探测器的第一个升级，旨在继续在未来十年中以检测器的下一个重大改进计划继续并加强该计划。拟议的计划包括完成LHCB上游追踪器的构建，以及该小组的构建，以及一个重点，以及一个关键的焦点，以及一项重点，以及一个关键的焦点，以及一项重点，以及一项重点，以及一项重点，以及一项重点，以及一项重点。运行1和2的LHCB以及未来三年实验操作中的预期数据3。物理学研究计划的重点是与B膜衰减中两个当前异常相关的测量：（1）在半甲基繁殖B衰减中与Lepton Flavor的出发点的暗示，当前的Lepton Beverational n semileptonic B衰变和（2）CP的研究中，cp nekist outer（2）cp n of cp n of cp n of cp n of cp n of cp n of cp n of cp n of cp n of cp n of cp n of cp n of cp n of cp in n of c. CP不对称偏离了基于Isosspin对称性的预期模式 - 长期存在的所谓“Kπ”拼图。如果确认，这些异常可能是由于在风味过程中存在新的物理作用。该计划还包括参与LHCB检测器升级II的下一个重大升级II的发展，这将导致风味过程的精确度得到显着提高。在目前的精度水平上，目前与标准模型预测相一致的关键风味可观察物的测量值对能量量表和新物理模型的结构施加了严重的约束。但是，从SM的出发领域正在出现，例如半杀解性B衰变中Lepton非宇宙性的迹象，这些迹象对新标量的存在非常敏感。根据LHCB及其升级检测器的数据，预计某些关键领域的未来测量值将达到所需的灵敏度，以阐明这些异常中的某些异常或进一步增强与SM预测的不同。这些结果可以与能源边界的研究一起，指向SM SM之外的物理结构的道路。该奖项反映了NSF的法定任务，并通过使用基金会的知识分子优点和更广泛的影响评估审查标准，认为通过评估被认为是宝贵的支持。