Low Latency Hardware Track Triggering and Searches for Long-Lived Particles with the ATLAS Detector

对大型强子对撞机的高亮度升级最终将增加瞬时亮度，因此，每个束交叉的p-p相互作用的数量将上升近一个数量级，达到200。ATLAS探测器将进行升级，包括数据采集系统中的新跟踪系统（ITk）和计划中的硬件跟踪触发器（HTT）。对于检测器的小区域（rHTT）， HTT必须能够以1MHz的速率处理事件，对于整个检测器（gHTT）， HTT必须能够以100KHz的速率处理事件。因此，高速处理是必不可少的，需要使用专用电子设备。通过这个项目，我们将为英特尔Stratix 10 MX fpga开发一种优化的轨迹模式识别算法，并将该解决方案与其他技术（包括asic， gpu和通用cpu）进行基准测试。根据测试结果，该项目要么进一步发展FPGA解决方案，要么过渡到对FPGA内的轨迹参数确定进行基准测试——这是HTT设计的另一个关键方面。该项目的另一个方面是寻找新的长寿命粒子。触发器中的跟踪信息对于识别大量模型至关重要。然而，由于轨迹触发数据在本项目中不可用，我们将重点关注具有发现潜力的Run 2和部分Run 3 ATLAS数据集的搜索。毫无疑问，观察长寿命粒子的衰变将证实超越标准模型的物理学的存在，并彻底改变我们对宇宙的理解。

The High Luminosity upgrade to the LHC will ultimately increase the instantaneous luminosity and, as a consequence, the number of p-p interactions per bunch crossing will rise nearly an order of magnitude to 200. The ATLAS detector will be upgraded including a new tracking system (ITk) and planned hardware track trigger (HTT) in the data acquisition system.The HTT must be able to process events at a rate of 1MHz for a small region (rHTT) of the detector and 100KHz for the full detector (gHTT). Therefore, high-speed processing is essential requiring the use of dedicated electronics. With this project, we will develop an optimized track pattern recognition algorithm for Intel Stratix 10 MX FPGAs and benchmark this solution against other technologies including ASICs, GPUs, and generic CPUs. Depending on the results, the project will either evolve to further the FPGA solution or transition to benchmarking the track parameter determination within an FPGA - another critical aspect of the HTT design.The other aspect of the project is the search for new long-lived particles. Track information in the trigger is critical for the identification of a host of models. However, since track-triggered data will not be available during this project, we will focus on a search with the Run 2 and partial Run 3 ATLAS dataset which has discovery potential. Observing the decay of long-lived particles would, without a doubt, confirm the existence of physics beyond the standard model and revolutionize our understanding of the universe.