U.S. CMS Upgrades for the High-Luminosity Large Hadron Collider

通过几十年的前期研究，科学家们开发出了粒子物理的标准模型，这是一个定量描述放射性、光与物质的相互作用和原子核结构等物理现象的理论框架。标准模型中最后一个到位的部分是希格斯玻色子，这种粒子与标准模型的其他成分相互作用，产生不同的质量。它于2012年在欧洲核子研究中心被发现，导致2013年诺贝尔物理学奖授予彼得·希格斯和弗朗索瓦·恩格勒。标准模型是不完整的，因为它没有解释例如暗物质和暗能量的天体物理观测等现象，也没有解释为什么反物质如此罕见。研究人员想要调查，是否有更多具有奇异性质的粒子，不同于迄今观察到的任何形式的物质，它们的存在是通过一些扩展了标准模型的理论来预测的。进一步研究希格斯玻色子的性质可能会揭示这些问题，但这将需要比迄今产生的数据样本大得多的数据样本。欧洲核子研究中心正在升级大型强子对撞机，以产生更多的质子-质子碰撞。在2027年完成升级后，届时它将被称为高亮度大型强子对撞机(HL-LHC)，相互作用速度将比发现希格斯玻色子时快约10倍。同时，CMS(紧凑型Muon螺线管)探测器将升级为在强度更高的HL-LHC环境中运行，它将包括关键的希格斯玻色子探测灵敏度增强。升级活动是一项国际协调努力，由欧洲核子研究中心管理，全球有40多个供资机构参与和个人捐款。美国国家科学基金会将向康奈尔大学拨款7722.5万美元，作为由31所美国大学组成的财团的牵头机构，该财团将制造和交付CMS探测器升级的关键部件：额外的硅探测器将探测非常接近入射质子束方向的电荷粒子；额外的电子读数系统将改进对碰撞中产生的粒子的能量和方向的角度测量；以及更复杂的电子和软件，用于从将产生的洪流中选择数据进行记录。NSF正在与美国能源部协调其参与，后者也为CMS升级的部分内容提供资金。这延续了一种非常成功的机构间伙伴关系，这种伙伴关系使美国科学家能够参与大型强子对撞机20多年来的尖端研究。康奈尔大学及其30个子获奖者将利用NSF奖来增加数百名本科生和高中生参与物理研究的多样性。亲身参与探测器制造和测试将使广泛的独特教育和外展活动与院校的本科生和研究生课程相结合。这些将推进NSF促进STEM(科学、技术、工程、数学)劳动力发展的目标。这一奖项反映了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。

Through decades of prior research, scientists have developed the Standard Model of Particle Physics, a theoretical framework that quantitatively describes physical phenomena such as radioactivity, the interaction of light with matter, and the structure of nuclei. The last piece of the Standard Model to fall into place was the Higgs boson, the particle whose interaction with other components of the Standard Model gives rise to their various masses. It was discovered at CERN in 2012, resulting in the award of the 2013 Nobel Prize in Physics to Peter Higgs and Francois Englert. The Standard Model is incomplete, as it does not explain, for example, phenomena such as the astrophysical observations of Dark Matter and Dark Energy, or why anti-matter is so rare. Researchers want to investigate whether there are additional particles with exotic properties, unlike any forms of matter observed so far, whose existence is predicted by some theories that extend the Standard Model. Further study of the properties of the Higgs boson may shed light on these questions, but this will require a far greater data sample than that produced so far. CERN is upgrading the LHC to produce a much larger number of proton-proton collisions. After upgrading is complete in 2027, when it will be known as the High Luminosity LHC (HL-LHC), the rate of interaction will be about ten times greater than when the Higgs boson was discovered. Concurrently, the CMS (Compact Muon Solenoid) detector will be upgraded to operate in the much-higher-intensity HL-LHC environment, and it will incorporate critical Higgs boson detection sensitivity enhancements. The upgrade activities are an internationally coordinated effort, managed by CERN and involving the participation and individual contributions of more than 40 funding agencies globally. NSF will award $77.225 million to Cornell University as the lead institution in a consortium of 31 US universities that will fabricate and deliver key elements of the CMS detector upgrade: additional silicon detectors that will detect charge particles travelling very close to the direction of the incident proton beams, additional electronic readout systems that will improve angular measurements of the energies and directions of particles produced in collisions, and more sophisticated electronics and software to select data for recording from among the torrent that will be produced. NSF is coordinating its participation with the US Department of Energy, who is also funding elements of the CMS upgrade. This continues a highly successful inter-agency partnership that has jointly enabled US scientists to participate in cutting edge research at the LHC for more than two decades. Cornell University and its 30 subrecipients will leverage the NSF award to increase the diversity of participation in physics research by hundreds of undergraduate and high school students. Hands-on involvement in detector fabrication and testing will enable a broad range of unique education and outreach activities that are coupled to institutional undergraduate and graduate programs. These will advance NSF goals promoting STEM (Science, Technology, Engineering, Mathematics) workforce development.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.