Intensity Frontier Physics Studies with b and c Quarks at LHCb

LHCb 中 b 和 c 夸克的强度​​前沿物理研究

• 批准号: 1507572
• 负责人: Sheldon Stone
• 金额: $ 319.5万
• 依托单位: Syracuse University
• 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: 2015-06-15 至 2019-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1507572&HistoricalAwards=false
• 关键词: Intensity; Frontier; Physics; Studies; Quarks

OverviewOne 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. These include why matter dominates over anti-matter in the Universe (CP violation), the values of the masses of the fundamental constituents, the quarks and the leptons, the size of the mixings among the quarks, and separately among the leptons, and the properties of dark matter. Most explanations require the presence of new forces, which we call Beyond the Standard Model Physics (BSM).The LHC is the premier High Energy Physics particle accelerator in the world and is currently operating at the CERN laboratory near Geneva Switzerland. It is one of the foremost facilities for answering these BSM questions.LHCb is the first experiment designed specifically to study the decays of hadrons containing b or c quarks at a hadron collider. The goal of LHCb is to identify new physics in nature by examining the properties of hadrons containing these quarks. New physics, or new forces, are manifest by particles, as yet to be discovered, these particles would modify decay rates and CP violating asymmetries, and thus allow new phenomena to be observed indirectly. In direct searches for new particles, the accelerator's energy must be high enough to allow the particle to be produced. In indirect searches effects of new particles can be seen even if they have a much higher mass than can be seen directly, because the effects are quantum in nature, and appear in Feynman diagrams where the particles are "virtual", so they are emitted and absorbed over short times. LHCb has operated very successfully starting in late 2010. The data are being analyzed and published. The experiment has shown many results, but none so far have clearly demonstrated new physics. LHCb has proposed an upgrade to be completed in the 2018-2019 time-frame when the LHC accelerator will not be running. This upgrade will allow LHCb to collect an order of magnitude more data in decay modes that will either show new physics or severely restrict the allowed mass range. LHCb is comprised of about 10 different sub-detectors or sub-systems. The Syracuse group has the responsibility of upgrading a part of the charged particle tracking system currently called the "TT." The intent is to significantly enhance the capabilities of this system above and beyond the requirement that data can be taken at an order of magnitude higher luminosity.Intellectual MeritThe intellectual merit of this award lies in the leading role the Syracuse group plays in the physics analysis that it is part of LHCb. This analysis sheds light on important aspects of our understanding of the Standard Model, including Charge Parity asymmetry which could explain the preponderance of matter in the universe as opposed to antimatter. In addition, the upgraded LHCb detector will allow a much more sensitive search for BSM physics. The main deliverable will be a new inner tracking device, the UT. This device will increase the data throughput over the current tracking device by an order of magnitude, allowing the LHCb experiment to probe BSM physics. The UT, which replaces the current tracker, will consists of four planes of single-sided 250-micron-thick silicon strip detectors, read out by a custom-made front-end electronic integrated circuit. With its reduced material budget and optimized segmentation as a function of the distance from the beam line, it plays a crucial role in reducing the rate of fake tracks and in providing fast momentum measurements in the residual field of the dipole magnet. The broader impacts of this work span several areas. Undergraduate and graduate students will be direct participants in the construction and testing of the detector that will be constructed. For many years a steady stream of undergraduates have been working in the PIs laboratories, where it is a tradition to ensure that graduate students have both hardware experience as well as data analysis capabilities. The upgrade work will be integrated into the Syracuse Quarknet program to involve high school teachers and some of their better students as well. Test results from this detector will be discussed at conferences and published. This detector is an integral part of the LHCb Upgrade and is essential for LHCb to continue to produce cutting edge physics results.

概述20世纪世纪的主要学术成就之一是粒子物理学标准模型（SM）的发展。该模型成功地将当时已知的所有基本粒子分类为具有相似量子特性的组的层次结构。最近，欧洲核子研究中心的大型强子对撞机发现了希格斯玻色子，证实了这一模型的有效性。然而，目前存在的标准模型留下了许多关于宇宙的问题。这些问题包括为什么宇宙中物质比反物质占主导地位（CP破坏），基本成分夸克和轻子的质量值，夸克之间和轻子之间混合的大小，以及暗物质的性质。大多数解释需要新的力量的存在，我们称之为超越标准模型物理（BSM）。LHC是世界上首屈一指的高能物理粒子加速器，目前在瑞士日内瓦附近的欧洲核子研究中心实验室运行。 LHC B是第一个在强子对撞机上专门研究含有B或c夸克的强子衰变的实验。LHCb的目标是通过检查包含这些夸克的强子的性质来识别自然界中的新物理。新的物理学或新的力量是由粒子表现出来的，这些粒子将改变衰变率和CP违反不对称性，从而允许间接观察到新的现象。在直接寻找新粒子时，加速器的能量必须足够高，以允许粒子产生。在间接搜索中，即使新粒子的质量比直接看到的大得多，也可以看到它们的效应，因为这些效应本质上是量子的，并且出现在费曼图中，其中粒子是“虚拟的”，因此它们在短时间内被发射和吸收。LHCb从2010年底开始非常成功地运作。数据正在分析和发布。实验已经显示了许多结果，但迄今为止还没有一个明确证明了新的物理学。LHCb计划在2018-2019年完成升级，届时LHC加速器将停止运行。这次升级将允许LHCb在衰变模式下收集更多数量级的数据，这些数据要么显示新的物理学，要么严重限制允许的质量范围。LHCb由大约10个不同的子探测器或子系统组成。锡拉丘兹小组负责升级目前称为“TT”的带电粒子跟踪系统的一部分。“其目的是显着提高该系统的能力，超出了要求，数据可以采取在一个数量级更高的光度。智力价值这个奖项的智力价值在于领先的作用，锡拉丘兹集团在物理分析，它是LHCb的一部分。这一分析揭示了我们对标准模型理解的重要方面，包括电荷宇称不对称性，它可以解释宇宙中物质相对于反物质的优势。此外，升级后的LHCb探测器将允许对BSM物理进行更灵敏的搜索。主要的交付将是一个新的内部跟踪装置，UT。该设备将使当前跟踪设备的数据吞吐量增加一个数量级，从而使LHCb实验能够探测BSM物理。取代电流跟踪器的UT将由四个单面250微米厚的硅条探测器组成，由定制的前端电子集成电路读出。凭借其减少的材料预算和优化的分割作为到束线的距离的函数，它在降低假轨道率和在偶极磁体的剩余场中提供快速动量测量方面发挥着至关重要的作用。这项工作的广泛影响跨越几个领域。本科生和研究生将直接参与将建造的探测器的建造和测试。多年来，一直有源源不断的本科生在PI实验室工作， 这是一个传统，以确保研究生既有硬件经验，以及数据分析能力。升级工作将被整合到锡拉丘兹夸克网计划，涉及高中教师和他们的一些更好的学生以及。该探测器的测试结果将在会议上讨论并发表。该探测器是LHCb升级的一个组成部分，对于LHCb继续产生尖端物理结果至关重要。