Indirect Dark Matter Search with Solar Neutrinos 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。间接探测实验试图观察太阳中暗物质粒子与质子相互作用的证据，最终导致对湮灭。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。DarkSide-20k将具有前所未有的灵敏度来探测太阳中微子，包括太阳中微子通量的CNO和Be-7成分。这个学生项目是通过在DarkSide-20k实验中测量Be-7和CNO太阳中微子通量的相对比例，致力于首次寻找太阳暗物质捕获改变恒星内热传输的证据。为了获得对CNO中微子的灵敏度，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。该项目将开发太阳中微子引起的电子反冲的方向测量，以便在暗物质搜索中首次使用方向性来减少背景。该项目将有助于建造和启用否决权探测器，并开发分析数据的分析工具。目标是开发一种间接的暗物质搜索分析，灵活地搜索太阳中暗物质捕获的信号，包括WIMP暗物质假说之外的奇异暗物质候选者。

The nature of dark matter is one of the fundamental questions about the universe today, at the forefront of physics research. Indirect detection experiments seek to observe evidence of interactions of dark matter particles with protons in the sun, leading ultimately to pair annihilation. 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 unprecedented sensitivity to detect solar neutrinos, including both CNO and Be-7 components of the solar neutrino flux.This studentship project is to work on development of the first search for evidence of dark matter capture in the sun modifying heat transport within the star, by measuring the relative proportions of the Be-7 and CNO solar neutrino fluxes in the DarkSide-20k experiment. To gain sensitivity to CNO neutrinos, 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 develop direction measurement of solar neutrino-induced electron recoils, in order to reduce backgrounds using directionality for the first time in a dark matter search. This project will contribute to building and commissioning the veto detector and develop analysis tools to analyse data. The goal is to develop an indirect dark matter search analysis with flexibility to search for signals of dark matter capture in the sun, including exotic dark matter candidates beyond the WIMP dark matter hypothesis.