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难以获得的能量体系研究的新纪元。希格斯玻色子的发现是大型强子对撞机计划的第一个主要亮点，该计划确立了标准模型(SM)的预测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对新物理的搜索，主要是使用13TeV质心能量记录的数据。物理分析活动形成了一个全面的计划，以扩展对希格斯玻色子性质的表征。该项目将分析由欧洲核子研究中心大型强子对撞机的ATLAS实验收集的数据。这项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推测性超越标准模型搜索。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方面的活动。鉴于希格斯粒子在标准模型电弱对称破缺中的关键作用，以及作为唯一已知的基本标量粒子，对其性质的探索是粒子物理的核心。为此，该项目包括对WW产生的研究，以了解Higgs玻色子在矢量玻色子散射中的作用，并通过改进的四次耦合在玻色子散射中寻找新的物理，研究Higgs玻色子在相关产生中的性质，重点是新建立的底部-反底部衰变模式，基于JET子结构技术和改进的b标记，将敏感性扩展到更高的横向动量，并搜索稀有和BSM模式。石溪集团负责液氩量热计的运营，包括第一阶段升级液氩后端升级电子设备的安装和调试，以及硅探测器运营的责任。他们参与了ATLAS跟踪器的升级研发，并负责HL-LHC液氩热量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尖端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小组参与石溪REU计划。该项目包括一个学生和社区教育项目，最初将在石溪举办，然后在更广泛的范围内举办。该组织还参与了当地的QuarkNet努力，并将主办2020年希格斯耦合会议，其中将包括一个公开日，包括演讲和小组讨论。该奖项反映了NSF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。

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.