An Effective Field Theory Dark Matter Search Using High Energy Nuclear Recoil in the LZ Experiment.

暗物质的存在是由天体物理学和宇宙学观测得到的，但到目前为止，还没有被直接观测到。LuxZeplin（LZ）探测器是世界上最灵敏的液体氙探测器，其主要物理目标是寻找“弱相互作用物质粒子”（WIMP）暗物质。在第一次科学运行（SR 1）取得成功之后，第二次科学运行（SR 2）目前正在进行数据收集阶段，主要目标是对SR 2数据进行有效场论（EFT）分析：将搜索区域扩展到比标准低能WIMP搜索更高的反冲能。这是由于几个更复杂的暗物质相互作用模型预计将在更高的能量下发生。除了主要的分析任务外，还将做出其他几项贡献，包括：升级当前的分析管道，使用更现代的计算架构，特别是GPU集群;改进模拟，从而提高背景分辨力;该项目福尔斯STFC粒子天体物理学研究领域，支持问题C4 -“暗物质和暗能量的性质是什么？".这项研究是作为LuxZeplin合作的一部分进行的。

The existence of Dark Matter is well motivated from astrophysical and cosmological observations but, as yet, has not been observed directly. The LuxZeplin (LZ) detector is the world most sensitive liquid xenon detector with the main physics goal is to search for "weakly interacting matter particle" (WIMP) dark matter. After a successful science run 1 (SR1), science run 2 (SR2) is currently ongoing in the data collection phase.Main objective of this project is to perform an effective field theory (EFT) analysis of SR2 data: extending the search region out to higher recoil energies than standard low energy WIMP search. This is motivated by the fact the several more complex dark matter interaction models are expected to occur at higher energies. The result will be either the discovery of a new dark matter candidate particle, or the setting of world leading limits on EFT coupling parameters.In addition to the main analysis task, several other contributions will be made including: upgrading the currently analysis pipeline to use more modern computational architectures, especially GPU clusters; improving simulations which in turn will improve background discrimination; improvement of current background models - likely with the use of machine learning.The project falls within the STFC Particle Astrophysics research area supporting question C4 - "What is the nature of Dark Matter and Dark Energy?". The research is performed as part of the LuxZeplin Collaboration.