Collaborative Research: Construction of the Upstream Tracker for the LHCb Upgrade

20世纪最重要的智力成就之一是粒子物理学标准模型的发展。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在欧洲核子研究中心的大型强子对撞机（LHC）上被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。这些问题包括为什么物质在宇宙中支配反物质（CP违反），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。大多数解释都需要新的力的存在，我们称之为超越标准模型物理学（BSM）。大型强子对撞机是世界上首屈一指的能量前沿粒子加速器，目前在瑞士日内瓦附近的欧洲核子研究中心实验室运行。它是回答这些BSM问题的最重要的工具之一。大型强子对撞机美丽夸克（LHCb）是第一个专门设计用于研究强子在强子对撞机上含有美丽夸克或迷人夸克的强子衰变的实验。LHCb的目标是通过检测含有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，是由尚未被发现的粒子表现出来的。这些粒子将改变衰变速率和CP违反不对称，从而允许间接观察到新的现象。在直接寻找新粒子时，加速器的能量必须高到足以产生新粒子。在间接搜索中，即使新粒子的质量比直接观察到的高得多，也能看到它们的效应，因为这种效应本质上是量子的，并且在计算中出现，粒子是“虚的”，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行。这些数据正在被分析和公布。这个实验显示了许多结果，但到目前为止还没有一个清楚地证明了新的物理学。LHCb提议在2018-2019年期间完成升级，届时LHC加速器将不再运行。这次升级将允许LHCb在衰变模式中收集一个数量级的数据，这些数据要么显示新的物理特性，要么严格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。参与该奖项的锡拉丘兹、马里兰州、辛辛那提和麻省理工学院小组负责升级部分带电粒子跟踪系统。其目的是显著提高该系统的能力，而不是要求数据可以在一个数量级更高的亮度下获取。该奖项的学术价值在于，它是LHCb升级的一部分，将允许对BSM物理进行更灵敏的搜索。交付的主要产品将是一个新的内部跟踪装置，上游跟踪器（UT）。该装置将比目前的跟踪装置增加一个数量级的数据吞吐量，使LHCb实验能够探测BSM物理。UT将取代目前的跟踪器，由四层单面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。由于其减少的材料预算和优化的分割作为距离束流线的函数，它在减少假轨道率和在偶极磁体残余场中提供快速动量测量方面起着至关重要的作用。更广泛的影响这项工作的更广泛的影响跨越几个领域。本科生和研究生将直接参与将要建造的探测器的建造和测试。多年来，源源不断的本科生和研究生一直在pi的实验室工作，确保研究生既有硬件经验又有数据分析能力是一项传统。升级工作将被整合到锡拉丘兹夸克计划中，让高中教师和他们的一些优秀学生也参与其中。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继续产生前沿物理结果至关重要。

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 (LHC)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 Energy Frontier 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.Large Hadron Collider beauty (LHCb) is the first experiment designed specifically to study the decays of hadrons containing beauty or charm 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 accelerators' 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 calculations 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, Maryland, Cincinnati and MIT groups participating in this award have the responsibility of upgrading a part of the charged particle tracking system. 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 is that it is part of an upgrade of LHCb that will allow a much more sensitive search for BSM physics. The main deliverable will be a new inner tracking device, the Upstream Tracker (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. Broader ImpactsThe 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 undergraduate and graduate students 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.