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

基本信息

批准号：
2012793
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：
2020
资助国家：
美国
起止时间：
2020-06-30 至 2023-06-29
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2012793&HistoricalAwards=false
关键词：
Experimental Study Heavy Flavor CP

项目摘要

A major focus of experimental particle physics research is on the search for physics beyond the Standard Model. Flavor physics plays a key role in this endeavor via precision measurements of ﬂavor processes sensitive to quantum loop effects, which complement direct searches at the highest energy accelerators. The physics reach of the LHCb experiment at the CERN LHC collider includes precision measurements of rare decays and matter-antimatter asymmetry in the charm quark and the bottom quark systems. At the current level of precision, these measurements impose severe constraints on the energy scale and the structure of new physics models. However, areas of deviations from the Standard Model are emerging, including signs of lepton non-universality in radiative and semi-leptonic B decays, which are highly sensitive to the presence of new scalar particles. The precision of future measurements in some key areas is expected to reach the required sensitivity to clarify these anomalies or further strengthen the deviations from the Standard Model predictions. These results could, in conjunction with studies at high energies, point the way to the structure of the physics beyond the Standard Model. This project involves a Maryland experimental particle physics group study of heavy flavor and CP violation with the LHCb experiment. It includes the development and construction of off-detector electronics for the upstream tracker for the LHCb detector upgrade and the installation and commissioning of the tracker, as well as major participation in the physics analysis of recorded and future LHCb data. The physics analysis effort is focused on measurements related to two current anomalies in the decays of B mesons: hints of departure from Lepton Flavor Universality in semileptonic B decays and the longstanding “Kaon pion” puzzle, where the measured CP asymmetries in the family of B to Kaon plus pion decays deviate from expectations. These anomalies, if confirmed, could be due to the imprints of new physics on flavor processes. Several data analysis techniques will be developed and used, including the use of machine learning. The ﬁndings of new sources of CP violation beyond the SM will have a profound impact on the understanding of the origin of baryon-antibaryon asymmetry and the ﬁeld of cosmology. The studies of ﬂavor processes will also yield precision information on the decay properties of the bottom and charmed hadrons, serving as a powerful testing ground for the predictions of lattice QCD calculations. The group’s detector upgrade eﬀort provides excellent opportunities for training undergraduate students in experimental and engineering techniques. The group works closely with an outreach program run by the physics and astronomy departments at the University of Maryland, the 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 group plans to expand this eﬀort to data analysis with the LHCb data by introducing students to advanced data handling and analysis techniques, such as machine learning.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.

实验粒子物理研究的主要重点是在标准模型之外寻找物理学。风味物理学在这项努力中通过对量子环效应敏感的精确测量来起关键作用，该过程对最高的能量加速器进行了直接搜索。 CERN LHC对撞机的LHCB实验的物理范围包括对Charm Quark和底部夸克系统中稀有腐烂和物质抗对称不对称的精确测量。在目前的精度水平上，这些测量值对新物理模型的能量量表和结构施加了严重的限制。然而，脱离标准模型的出发区域正在出现，包括在辐射和半膜的B衰减中的Lepton非宇宙性迹象，这对新标量颗粒的存在非常敏感。预计某些关键领域中未来测量的精度将达到所需的灵敏度，以阐明这些异常或进一步加强与标准模型预测的偏离。这些结果可以与高能量的研究一起，指向超出标准模型的物理结构的道路。该项目涉及马里兰州实验粒子物理小组对LHCB实验的重型风味和CP违反的研究。它包括为LHCB检测器升级的上游跟踪器开发和构建，以及跟踪器的安装和调试，以及对记录和未来LHCB数据的物理分析的主要参与。物理分析工作的重点是与B介子衰减中的两个当前异常相关的测量：半衰减B衰减中的Lepton风味普遍性的提示和长期存在的“ Kaon Pion”拼图，其中测量的CP不对b to b to Kaon plus to to Kaon plus plus plus plus pion depperiations versivations verciations verciations cantecipations verciatiations cantecations cande cantecations cande sate catways cantecations。如果确认这些异常可能是由于新物理学上的风味过程造成的。将开发和使用几种数据分析技术，包括使用机器学习。 SM之外的CP违规来源的发现将对对Baryon-Antibaryon不对称起源和宇宙学领域的起源的理解产生深远的影响。对摩avor过程的研究还将产生有关底部和迷人的黑龙的衰减特性的精确信息，这是晶格QCD计算预测的有力测试场。该小组的探测器升级效果为培训实验和工程技术的本科生提供了绝佳的机会。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，该计划旨在为马里兰州和华盛顿地区社区学院中代表性不足的团体的本科生提供研究和培训机会。该小组计划通过向学生介绍高级数据处理和分析技巧，例如机器学习，将此效果扩展到数据分析，例如机器学习。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛的影响审查标准来评估通过评估来获得的支持。