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

10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领域研究的新时代。希格斯玻色子的发现是LHC计划的第一个主要亮点，它确定了标准模型（SM）的预测粒子内容和相互作用是完整的。尽管成功，SM被广泛认为是一个不完整的理论。正在进行的研究必须确定这种新的希格斯玻色子是否是SM的玻色子，新的实验数据对于发现大自然是否以及如何选择扩展SM至关重要。这些研究包括新的测量和寻找新的物理学，主要使用13 TeV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，以扩展希格斯玻色子属性的表征。该项目将分析在欧洲核子研究中心的大型强子对撞机上进行的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投机性超越标准模型搜索。此外，斯托尼布鲁克小组将领导ATLAS维护和操作、算法开发和探测器升级方面的活动。由于希格斯玻色子在标准模型电弱对称性破缺中扮演着关键角色，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，该项目包括研究WW产生，以了解希格斯玻色子在矢量玻色子散射中的作用，并通过玻色子散射中修正的四次耦合寻找新的物理学，研究相关产生中希格斯玻色子的性质，重点是新建立的底-反底衰变模式，根据喷流子结构技术和改进的b-标记，将灵敏度扩展到更高的横向动量，并搜索稀有和BSM模式。斯托尼布鲁克小组负责液氩量热计的操作，包括第一阶段升级液氩后端升级电子设备的安装和调试，并负责硅探测器的操作。他们参与了ATLAS跟踪器升级研发，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的研究活动和通过集团的参与参与斯托尼布鲁克REU计划。该项目包括一个学生和社区教育计划，最初将在斯托尼布鲁克举办，然后更广泛。该组织还参与了当地的QuarkNet工作，并将主办希格斯耦合2020会议，其中将包括一个公共日与讲座和小组讨论。该奖项反映了NSF的法定使命，并已被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

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.