Experimental Studies of the Higgs Mechanism in the Standard Model and Beyond

十年前，大型强子对撞机（LHC）的启动，开启了迄今为止无法进入的能源体系研究的新时代。希格斯玻色子的发现是大型强子对撞机项目的第一个主要亮点，它确定了标准模型（SM）预测的粒子含量和相互作用是完整的。尽管取得了这样的成功，但人们普遍认为SM是一个不完整的理论。正在进行的研究必须确定这个新的希格斯玻色子是否是SM的玻色子，而新的实验数据对于发现大自然是否以及如何选择扩展SM是必不可少的。这些研究包括新的测量和寻找新的物理，主要使用在13 TeV的质心能量记录的数据。物理分析活动形成了一个全面的程序来扩展希格斯玻色子性质的表征。该项目将分析欧洲核子研究中心大型强子对撞机ATLAS实验收集的数据。研究包括标准模型双玻色子测量，希格斯玻色子衰变特性，以及涉及希格斯玻色子产生和衰变的超越标准模型的推测性搜索。此外，石溪小组将领导ATLAS维护和操作、算法开发和探测器升级等活动。由于希格斯粒子在标准模型电弱对称性破缺中发挥着关键作用，同时也是唯一已知的基本标量粒子，因此对其性质的探索是粒子物理学的核心。为此，本项目包括研究WW产生，以了解希格斯玻色子在矢量玻色子散射中的作用，并通过改进玻色子散射中的四次耦合寻找新的物理，研究希格斯玻色子在相关产生中的性质，重点研究新建立的底-反底衰变模式，基于喷射子结构技术和改进的b标记扩展对更高横向动量的灵敏度。寻找稀有模式和BSM模式。石溪组负责液氩量热计的操作，包括安装和调试第一阶段升级液氩后端升级电子设备，并负责硅探测器的操作。他们参与了ATLAS跟踪器的升级研发，并负责HL-LHC液氩量热计读出数字处理器系统的设计、测试和生产。这项工作为本科生和研究生提供了参与前沿科学研究和仪器开发的机会。本科生有机会通过学年研究活动和通过石溪REU项目的小组参与参与。该项目包括一个学生和社区教育项目，最初在石溪分校举办，然后在更广泛的范围内举办。该小组还参与了当地QuarkNet的工作，并将主办希格斯耦合2020年会议，其中包括一个公开日的讲座和小组讨论。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知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The start-up of the Large Hadron Collider (LHC) a decade ago ushered in a new era of research in hitherto inaccessible energy regimes. The discovery of the Higgs boson is the first major highlight of the LHC program, which established that the predicted particle content and interactions of the Standard Model (SM) are complete. Despite this success, the SM is widely believed to be an incomplete theory. Ongoing studies must determine whether or not this new Higgs boson is that of the SM, and new experimental data are essential to discover if and how Nature has chosen to extend the SM. These studies include new measurements and searches for new physics, primarily using data recorded at a center-of-mass energy of 13 TeV. The physics analysis activities form a comprehensive program to extend characterization of Higgs boson properties.This project will analyze data collected with the ATLAS experiment at CERN’s Large Hadron Collider. The research includes standard model di-boson measurements, Higgs boson decay properties, and speculative Beyond–the–Standard–Model searches involving Higgs boson production and decay. In addition, the Stony Brook group will lead activities in ATLAS maintenance and operations, algorithm development, and detector upgrades. With the Higgs’ key role in standard model electroweak symmetry breaking, as well as being the only known elementary scalar particle, exploration of its properties is central to particle physics. To that end, this project includes studies of WW production to understand the role of the Higgs boson in vector boson scattering and searches for new physics through modified quartic couplings in boson scattering, studies of the properties of the Higgs boson in associated production focusing on the newly established bottom-antibottom decay mode, extending the sensitivity to higher transverse momenta based on jet substructure techniques and improved b-tagging, and searches for the rare and BSM modes. The Stony Brook group has responsibilities for liquid argon calorimeter operations including the installation and commissioning of the Phase I upgrade liquid argon Back End upgrade electronics, and responsibilities for silicon detector operations. They are involved in the ATLAS tracker upgrade R&D and have design, testing and production responsibilities for the HL-LHC liquid argon calorimeter read-out digital processor system.This work provides undergraduate and graduate students with the opportunity to participate in leading edge scientific research and instrumentation development. Undergraduate students have the opportunity to participate both through academic year research activities and through the group’s participation in the Stony Brook REU program. This project includes a program of student and community education to be initially hosted at Stony Brook and then more broadly. The group also participates in the local QuarkNet efforts and will host the Higgs Couplings 2020 conference, which will include a public day with lectures and a panel discussion.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.