Searches for New Phenomena at the Energy Frontier

该奖项将为在欧洲核子研究中心(CERN)的大型强子对撞机(LHC)上从事ATLAS实验的北伊利诺伊大学小组提供支持。CERN是一家位于瑞士日内瓦的粒子物理实验室。大型强子对撞机和大型粒子探测器ATLAS是利用美国国家科学基金会和世界各地其他机构的资金作为基础科学工具建造的。他们的主要目标之一是找到希格斯玻色子，这是历史上成功的“标准模型”(SM)中的最后一个粒子，它解释了宇宙中形成物质的已知粒子的存在和相互间的作用力。这一努力取得了成功。实验的下一步是研究这种新发现的粒子的性质和特征，作为实验室，看看它的行为是否如SM预测的那样，或者是否存在偏差，表明标准模型(BSM)之外的新物理证据，例如，可能解释神秘的“暗物质”的存在，这种物质构成了宇宙的如此大的质量。该小组将参与这些研究。大型强子对撞机目前正处于第二次运行中，能量几乎是之前探索的两倍，事件样本也显著增加。在这种更高的能量和来自当前运行的更高的事件统计数据下，通过进一步升级LHC和ATLAS，BSM物理的证据可能会出现。为了促进对Higgs玻色子的详细研究和寻找其他新的物质状态，NIU小组将把他们的研究重点放在Higgs耦合，包括自耦合，以确定这种粒子是标准模型中假设的唯一Higgs玻色子，还是在各种BSM场景中假设的多个中性标量玻色子之一。大部分的分析工作都集中在寻找迄今为止发现的唯一希格斯粒子的配对产生。此外，该小组长期以来一直对ATLAS搜索某些扩展希格斯模型中的带电希格斯玻色子感兴趣，并对希格斯玻色子衰变为两条伽马射线的微分截面测量感兴趣。NIU小组还参与了TileCAL、强子量热计和对能量和丢失能量测量至关重要的实验子系统的第二阶段升级，以及高级快速通道触发实验FTK，该实验是能够在大型强子对撞机光度增加时触发重要物理目标的核心。NIU小组活动的一个组成部分是与K-12学生、教师和普通公众进行接触。他们的计划包括在NIU的一个活跃的QuarkNet中心，该中心每年举办为期一天的大师班、为期一周的研讨会和6-8周的暑期实习。该组织还积极参与各种吸引公众参与的计划，其中一些由NIU主办，另一些由附近的费米国家加速器实验室主办。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。

This award will provide support to a Northern Illinois University group working on the ATLAS experiment at the Large Hadron Collider (LHC) at CERN, a particle physics laboratory in Geneva, Switzerland. The LHC machine and ATLAS, a large particle detector facility, were built as basic science tools using funds from NSF and other agencies around the world. One of their primary objectives was to find the Higgs Boson, the last particle in the historically successful "Standard Model" (SM) that accounts for so much of the existence of, and forces between, known particles forming the matter in the universe. This effort has been successful. The next step in the experiments is to study the properties and characteristics of this newly discovered particle as a laboratory to see if it behaves as the SM predicts or if there are deviations suggesting evidence for new physics Beyond the Standard Model (BSM) that might, for instance, account for the presence of the mysterious "Dark Matter" that makes up so much of the mass of the universe. This group will participate in these studies. The LHC is currently in the midst of Run 2, at almost twice the energy explored earlier and with significantly increased event samples. It is possible that evidence for BSM physics could emerge at this higher energy and with the higher event statistics from the current run and by means of further upgrades of the LHC and ATLAS to follow.To facilitate a detailed study of the Higgs Boson and search for other new states of matter, the NIU group will be focusing their studies on Higgs couplings, including self-coupling, in order to determine whether this particle is the sole Higgs boson postulated in the Standard Model, or one of multiple neutral scalar bosons postulated in various BSM scenarios. Much of the analytical effort is focused on searches for pair production of the only Higgs particle discovered so far. Additionally the group has had a long-standing interest in the ATLAS searches for charged Higgs bosons featured in certain extended Higgs models, and in differential cross section measurements of Higgs boson decays into two gamma rays. The NIU group is also engaged in the Phase 2 Upgrade of the TileCAL, hadronic calorimeter, and experimental subsystem essential for energy and missing energy measurements, and in advanced Fast Track Triggering for the experiment called the FTK, which is central to being able to trigger on important physics objectives as the LHC luminosity increases.An integral part of the NIU group activity is outreach to K-12 students, teachers, and the general public. Their program includes an active QuarkNet center at NIU that hosts annual one-day masterclasses, week-long workshops, and 6-8-week summer internships. The group is also active in a variety of programs to engage the public, some hosted at NIU and others at nearby Fermi National Accelerator Laboratory.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.