Indirect Dark Matter Search with Solar Neutrinos in the DarkSide-20k Experiment

暗物质的性质是当今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暗物质粒子与太阳中质子相互作用的证据，最终导致对湮灭。DarkSide-20 k是一个国际合作项目，致力于开发下一代用于低背景搜索的液氩探测器。50吨重的DarkSide-20 k探测器正在意大利Gran Sasso的LNGS实验室建造，计划于2023年开始首次运行。DarkSide-20 k将具有前所未有的探测太阳中微子的灵敏度，包括太阳中微子通量中的CNO和Be-7组分。本学生项目的工作是通过测量DarkSide-20 k实验中Be-7和CNO太阳中微子通量的相对比例，首次寻找太阳中暗物质捕获改变星星内热传输的证据。为了获得对CNO中微子的灵敏度，需要以前所未有的水平来理解背景。为此，正在开发世界领先的光电传感器技术和读数，这将允许识别信号和背景事件，同时最大限度地减少其自身的放射性足迹，这是最大限度地减少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诱导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探测器，并开发分析数据的分析工具。我们的目标是开发一种间接的暗物质搜索分析，具有灵活性，以搜索太阳中暗物质捕获的信号，包括超出WIMP暗物质假设的外来暗物质候选者。

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.