Upgrades of the Tracker and Trigger of the CMS experiment at the CERN LHC

为了能够对大型强子对撞机上预期的发现的物理学进行更深入的研究，以及加速器非常成功的性能带来的挑战，在未来几年内需要对一些关键的CMS子系统进行升级。此外，大型强子对撞机的运行预计将比实验设计的时间延长至少十年。对跟踪探测器不可避免的辐射损害将需要在2022年更换，新的探测器必须更具颗粒性和抗辐射能力。它还必须在更恶劣的环境中表现得更好，每个光束交叉处都有更高的事件堆积，才能达到所需的物理目标。大型强子对撞机是世界上能量最高的机器，也是唯一能够在可预见的未来研究一些最优先的基础物理课题的加速器。除了希格斯玻色子的发现有望完成标准模型之外，它还允许我们阐明粒子物理学中的许多其他关键问题，包括暗物质的性质、力的统一、基本粒子的存在及其在宇宙起源中的作用。对大型强子对撞机计划的投资是巨大的，对实验的升级将大大延长其工作寿命，并通过利用过去十年的技术进步来改善其性能。需要修改的最关键的子探测器是跟踪器和触发器，英国团队在这两个子探测器中发挥了重要作用，并在最近几年进行了成功的研发。我们建议在此基础上提供新的热量计触发系统的重要部分，并继续研发，将跟踪数据纳入未来的一级触发。我们将为新的像素探测器提供一个新的数据采集系统，并通过提供前端电子产品的主要部件来为未来的跟踪器建造探测器模块。在每一种情况下，英国都将提供硬件、固件和软件，提供大量的智力投入和领导角色。这些都是对总体CMS升级计划的重大贡献，符合按比例分担建设责任的原则。我们要求获得适当的资源，使我们能够开展这些项目。

To allow deeper investigations of the physics of discoveries expected at the LHC, and the challenges presented by the very successful performance of the accelerator, upgrades to some key CMS sub-systems are required in the next few years. In addition, LHC operation is expected to continue for at least a decade longer than the experiments were designed for. Inevitable radiation damage to the tracking detector will require its replacement in 2022 and the new detector must be more granular and radiation hard. It must also perform better in an even harsher environment, with higher pileup of events in each beam crossing, to meet the required physics goals.The LHC, which is the highest energy machine in the world, is the only accelerator capable of investigating some of the highest priority fundamental physics topics for the foreseeable future. In addition to the hoped for completion of the Standard Model by the discovery of the Higgs boson, it allows us to shed light on many other key questions in particle physics including the nature of dark matter, unification of forces, the existence of fundamental particles and their roles in the origin of the universe. The investment in the LHC programme has been significant and upgrades to the experiments will extend its working lifetime considerably, and improve their performance by taking advantage of technological progress in the last decade.The most crucial sub-detectors to be modified are the tracker and trigger, in which UK groups have played significant roles and have undertaken successful R&D in recent years. We propose to build on this by delivering a significant part of the new calorimeter trigger system and continuing R&D to incorporate tracking data into the future Level 1 trigger. We will deliver a new data acquisition system for the new pixel detector, and contribute to construction of detector modules for the future tracker by providing major parts of the front end electronics. In each case, the UK will be providing hardware, firmware and software with substantial intellectual input and leadership roles.These represent substantial contributions to the overall CMS upgrade plan consistent with proportionate sharing of construction responsibilities. We request appropriate resources to allow us to undertake these projects.