Physics Beyond Standard Model with the CMS Pixel Detector

使用 CMS 像素探测器实现超越标准模型的物理学

• 批准号: 1506168
• 负责人: Sudhir Malik
• 金额: $ 36.01万
• 依托单位: University of Puerto Rico Mayaguez
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1506168&HistoricalAwards=false
• 关键词: Physics; Beyond; Standard; Model; CMS

One of the major intellectual achievements of the 20th century was the development of the Standard Model (SM) of particle physics. This model succeeded in classifying all of the elementary particles known at the time into a hierarchy of groups having similar quantum properties. The validity of this model to date was recently confirmed by the discovery of the Higgs boson at the Large Hadron Collider at CERN. However, the Standard Model as it currently exists leaves open many questions about the universe, including such fundamental questions as to why the Higgs mass has the value it has. The Large Hadron Collider (LHC), operating at the CERN laboratory near Geneva Switzerland, is the premier Energy Frontier particle accelerator. It is currently one of the foremost facilities for answering Beyond the Standard Model questions and studying the properties of the Higgs boson. One of the primary functions of the Compact Muon Solenoid (CMS) experiment at the LHC is to discover new physics beyond the Standard Model. The work proposed here will analyze data from the CMS experiment, looking for signals of Beyond the Standard Model (BSM) physics. This award will fund two aspects of the CMS experiment: 1) further searches for BSM physics and 2) help build the CMS Phase I forward pixel detector (FPix) upgrade, which will enhance the ability of CMS to discover BSM physics. The CMS physics analysis supported by this award will focus on Supersymmetry(SUSY) and Dark Matter, both proposed BSM. A means of identifying b-quarks in the CMS data ( b-tagging) will be further developed and refined by this award. One SUSY candidate is the stop quark, the supersymmetric partner of the SM top quark. Decay products of stop quarks involve top quarks and b-tagging is the tool to find events with top quarks. In addition, events with directly produced top quarks serve as backgrounds to signal events that contain top squarks. The CMS Pixel Detector is the tool to efficiently provide precise tracking and b-tagging needed for SUSY searches. The award also provides important parts of the FPix upgrade which are being tested at FermiLab. The CMS Forward pixel upgrade will allow the precise vertex location, needed for all physics studies, even in the harsh environment (very high luminosity) expected in near future LHC running. The CMS Forward Pixel Detector uses state-of-the art silicon technology for particle detection combined with equally sophisticated readout electronics. Innovative techniques of radiation hard technology and bump bonding have been used in the current detector to meet the real estate challenges in a high radiation environment. These techniques would greatly enhance the life span of detectors used in outer space research and improve bio-sensing miniature devices for medical applications.

20世纪最重要的智力成就之一是粒子物理学标准模型（SM）的发展。这个模型成功地将当时已知的所有基本粒子划分为具有相似量子特性的等级。到目前为止，这个模型的有效性最近被欧洲核子研究中心大型强子对撞机发现的希格斯玻色子所证实。然而，目前存在的标准模型留下了许多关于宇宙的问题，包括为什么希格斯质量具有它所具有的价值这样的基本问题。位于瑞士日内瓦附近的欧洲核子研究中心实验室的大型强子对撞机（LHC）是首屈一指的能量前沿粒子加速器。它目前是回答超越标准模型问题和研究希格斯玻色子性质的最重要的设备之一。大型强子对撞机的紧凑型介子螺线管（CMS）实验的主要功能之一是发现超越标准模型的新物理。这里提出的工作将分析来自CMS实验的数据，寻找超越标准模型（BSM）物理的信号。该奖项将资助CMS实验的两个方面：1)进一步搜索BSM物理；2)帮助构建CMS第一阶段前向像素探测器（FPix）升级，这将增强CMS发现BSM物理的能力。该奖项支持的CMS物理分析将集中在超对称（SUSY）和暗物质上，两者都提出了BSM。该奖项将进一步发展和完善CMS数据中b-夸克的识别方法（b-tagging）。一个SUSY候选者是停止夸克，它是SM顶夸克的超对称伙伴。停止夸克的衰变产物涉及顶夸克，b标记是寻找顶夸克事件的工具。此外，直接产生顶夸克的事件可以作为包含顶夸克的事件的信号背景。CMS像素检测器是有效地提供SUSY搜索所需的精确跟踪和b标记的工具。该合同还提供了FPix升级的重要部分，这些部分正在FermiLab进行测试。CMS Forward像素升级将允许所有物理研究所需的精确顶点定位，即使在不久的将来LHC运行中预期的恶劣环境（非常高的亮度）中也是如此。CMS前向像素检测器使用最先进的硅技术进行粒子检测，并结合同样复杂的读出电子设备。目前的探测器采用了辐射硬技术和碰撞键合的创新技术，以应对高辐射环境下的房地产挑战。这些技术将大大提高用于外层空间研究的探测器的寿命，并改进用于医疗应用的生物传感微型装置。