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

实验粒子物理研究的一个主要焦点是寻找超越标准模型的物理。风味物理学通过精确测量对量子环效应敏感的flAvor过程，在这一努力中发挥了关键作用，这是对最高能量加速器的直接搜索的补充。欧洲核子研究中心LHC对撞机LHCb实验的物理范围包括精确测量魅力夸克和底夸克系统中的稀有衰变和物质-反物质不对称。在目前的精度水平上，这些测量对新物理模型的能量尺度和结构施加了严重的限制。然而，偏离标准模型的领域正在出现，包括辐射和半轻子B衰变中的轻子非普适性迹象，它们对新标量粒子的存在高度敏感。一些关键地区未来测量的精确度预计将达到必要的灵敏度，以澄清这些异常或进一步加强与标准模型预测的偏差。这些结果与高能研究相结合，可以为超越标准模型的物理结构指明方向。这个项目涉及马里兰州的一个实验粒子物理小组，通过LHCb实验研究重味道和CP破坏。它包括为LHCb探测器升级的上游追踪器开发和建造探测器外电子设备，安装和调试追踪器，以及主要参与记录的和未来的LHCb数据的物理分析。物理分析工作集中在与B介子衰变中的两个电流反常相关的测量上：半轻子B衰变中偏离轻子风味普适性的迹象和长期存在的“Kaon pion”之谜，在B到Kaon+pion衰变中测量到的CP不对称性偏离了预期。如果得到证实，这些异常现象可能是由于新物理学在风味过程中留下的印记。将开发和使用几种数据分析技术，包括使用机器学习。SM以外CP破坏的新来源的fi发现将对理解重子-反重子不对称的起源和宇宙学的fi场产生深远的影响。对flAvor过程的研究还将提供关于底部强子和魅力强子衰变性质的精确信息，为格子QCD计算的预测提供强有力的测试基础。该集团的探测器升级effort为本科生提供了在实验和工程技术方面进行培训的绝佳机会。该组织与马里兰大学物理系和天文学系运营的一个名为Grad-Map的外展项目密切合作，该项目旨在为马里兰和华盛顿地区社区大学中代表性不足群体的本科生提供研究和培训机会。该组织计划通过向学生介绍先进的数据处理和分析技术，如机器学习，将这一ff端口扩展到使用LHCB数据进行数据分析。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

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.