We present an overview of the High-Luminosity (HL-LHC) program at the Large Hadron Collider (LHC), its scientific potential and technological challenges for both the accelerator and detectors. The HL-LHC program is expected to start circa 2027 and aims to increase the integrated luminosity delivered by the LHC by an order of magnitude at the collision energy of 14 TeV. This requires upgrades to the injector system, accelerator complex and luminosity levelling. The two experiments, ATLAS and CMS, require substantial upgrades to most of their systems in order to cope with the increased interaction rate, and much higher radiation levels than at the current LHC. We present selected examples based on novel ideas and technologies for applications at a hadron collider. Both experiments will replace their tracking systems. We describe the ATLAS pixel detector upgrade featuring novel tilted modules, and the CMS Outer Tracker upgrade with a new module design enabling use of tracks in the level-1 trigger system. CMS will also install state-of-the-art highly segmented calorimeter endcaps. Finally, we describe new picosecond precision timing detectors of both experiments. In addition, we discuss how the upgrades will enhance the physics performance of the experiments, and solve the computing challenges posed by the expected large data sets. The physics program of the HL-LHC is focused on precision measurements probing the limits of the Standard Model (SM) of particle physics and discovering new physics. We present a selection of studies that have been carried out to motivate the HL-LHC program. A central topic of exploration will be the characterization of the Higgs boson. The large HL-LHC data samples will extend the sensitivity of searches for new particles or new interactions whose existence has been hypothesized in order to explain shortcomings of the SM. Finally, we comment on the nature of large scientific collaborations.

中文翻译：

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高亮度大型强子对撞机计划的科学潜力和技术挑战

我们概述了大型强子对撞机 (LHC) 的高亮度 (HL-LHC) 计划、其科学潜力以及对加速器和探测器的技术挑战。HL-LHC 计划预计将于 2027 年左右启动，旨在将 LHC 在 14 TeV 碰撞能量下提供的综合光度提高一个数量级。这需要升级喷射器系统、加速器复合体和光度调平。ATLAS 和 CMS 这两个实验需要对其大部分系统进行实质性升级，以应对增加的相互作用率和比目前的大型强子对撞机高得多的辐射水平。我们根据在强子对撞机中应用的新颖想法和技术展示了精选示例。这两个实验都将取代他们的跟踪系统。我们描述了具有新颖倾斜模块的 ATLAS 像素检测器升级，以及具有新模块设计的 CMS 外部跟踪器升级，可以在 1 级触发系统中使用轨道。CMS 还将安装最先进的高度分段量热计端盖。最后，我们描述了两个实验的新皮秒精度定时检测器。此外，我们还讨论了升级将如何提高实验的物理性能，并解决预期的大数据集带来的计算挑战。HL-LHC 的物理项目专注于精确测量，探索粒子物理标准模型 (SM) 的极限并发现新物理。我们展示了一系列为推动 HL-LHC 计划而开展的研究。探索的一个中心主题将是希格斯玻色子的特征。大型 HL-LHC 数据样本将扩展搜索新粒子或新相互作用的灵敏度，这些粒子或新相互作用的存在已被假设以解释 SM 的缺点。最后，我们评论了大型科学合作的性质。