Dark Matter Direct Detection in the DarkSide-20k Experiment

暗物质的本质是当今关于宇宙的基本问题之一，处于物理学研究的前沿。直接探测实验试图观察暗物质粒子与原子核的相互作用。DarkSide-20k是一个国际合作项目，致力于开发用于低背景搜索的下一代液态氩（LAr）探测器。50吨重的DarkSide-20k探测器正在位于意大利Gran Sasso的lng实验室中建造，计划于2023年开始首次运行。与目前对质量在TeV级的暗物质粒子的搜索相比，DarkSide-20k的灵敏度将提高两个数量级。本课题主要研究有源检测器的光电传感器、电子学、数据采集系统及仿真的开发。随着实验在寻找暗物质方面变得越来越敏感，背景需要在前所未有的水平上得到理解。为了做到这一点，世界领先的光敏技术和读数正在开发中，这将允许识别信号和背景事件，同时也最小化它们自己的放射性足迹，这是最小化暗物质搜索背景事件的关键要求。该项目将表征和校准光敏传感器硬件，有助于建造和调试否决权探测器，并开发分析工具来分析数据。目标是开发一种具有灵活性的暗物质搜索分析，以搜索包括WIMP暗物质假设之外的奇异暗物质候选信号。

The nature of dark matter is one of the fundamental questions about the universe today, at the forefront of physics research. Direct detection experiments seek to observe interactions of dark matter particles with atomic nuclei. DarkSide-20k is an international collaboration engaged in a staged program to develop the next generation of liquid argon (LAr) detectors for low-background searches. The 50 tonne DarkSide-20k detector is under construction in the LNGS laboratory, in Gran Sasso, Italy, first operations planned begin in 2023. DarkSide-20k will have two orders of magnitude increase in the sensitivity over current searches for dark matter particles with masses at the TeV scale.This studentship project is to work on development of the active veto detector photosensors, electronics, data acquisition system and simulation. As experiments become more sensitive in search of dark matter, backgrounds need to be understood at levels never before achieved. To do so, world-leading photosensor technology and readout are being developed that will allow the identification of signal and background events whilst also minimising their own radioactive footprint, a key requirement to minimise background events to the dark matter search.This project will characterise and calibrate the photosensor hardware, contribute to building and commissioning the veto detector and develop analysis tools to analyse data. The goal is to develop a dark matter search analysis with flexibility to search for signals including exotic dark matter candidates beyond the WIMP dark matter hypothesis.