Probing light dark matter and core-collapse supernova phenomena with neutrinos at SNO+

在 SNO 中利用中微子探测轻暗物质和核心塌缩超新星现象

• 批准号: 2584417
• 金额: --
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2584417
• 关键词: Probing; light; dark; matter; core

Mr Hewitt will investigate the sensitivity of SNO+ to light (sub-GeV) dark matter up-scattered by cosmic ray electrons and protons in the galactic halo, an idea prompted by a recent paper by Cappiello and Beacom (PRD 100 (2019) 10, 103011). These particles tend to evade dark matter direct detection experiments because of their low momentum, but they may leave up to O(10) MeV visible energy in SNO+. SNO+'s exceptionally low backgrounds could improve limits (calculated by Cappiello and Beacom based on other experimental data) for this relatively unexplored range of dark matter candidates. This part of the project involves different models of the galactic halo, cosmic rays, and simplified simulation of the propagation of exotic particles through 2km of the Earth's crust, followed by full Geant4-based detector simulation of individual events.The main focus of the second part of Mr Hewitt's project will shift to neutrinos from a (prospective but rare) galactic core-collapse supernova. He will seek to improve SNO+ sensitivity to pre-supernova neutrinos and the supernova burst by improving the detector's nearly real-time analysis of coincident events (indicative of inverse beta decay) and burst patterns (incorporating different charged and neutral-current processes). He will also investigate strategies for increasing SNO+ acceptance of neutrino events outside the main scintillator volume, a task which will involve detailed simulation and the development of novel reconstruction techniques in areas of the detector with complicated optics. As part of this investigation, he will examine whether it is possible to extract directional information from at least some of these largely water-based events, since such events may help localize the direction of the supernova - important information to relay as quickly as possible to the astronomical observer community via the global Supernova Neutrino Early Warning System (SNEWS) network. Mr Hewitt will also investigate the impact of a range of dark matter models on the observed time and energy spectra of the supernova neutrinos and other associated energy depositions in the detector. Understanding these effects will further inform SNO+ and other neutrino experiments as to the range of different phenomena which may be observed in the event of a galactic supernova, and improve the ability of SNEWS to produce timely, reliable, relevant information for subsequent real-time observations, as well as correlation with both electromagnetic and gravitational "messengers".

休伊特先生将研究SNO+对光（亚GeV）暗物质的敏感性，暗物质被银河系晕中的宇宙射线电子和质子向上散射，这一想法是由Cappiello和Beacom最近的一篇论文提出的（PRD 100（2019）10，103011）。这些粒子由于动量低，往往会避开暗物质直接探测实验，但它们可能会在SNO+中留下高达O（10）MeV的可见能量。SNO+异常低的背景可以改善这个相对未探索的暗物质候选者范围的限制（由Cappiello和Beacom基于其他实验数据计算）。这一部分的项目包括不同的星系晕模型、宇宙射线模型、奇异粒子在2公里地壳中传播的简化模拟，以及基于Geant 4的探测器对单个事件的完整模拟。休伊特项目第二部分的主要焦点将转移到来自（潜在但罕见的）星系核坍缩超新星的中微子。他将寻求通过改进探测器对重合事件（指示逆β衰变）和爆发模式（结合不同的带电和中性电流过程）的近实时分析来提高SNO+对超新星前中微子和超新星爆发的灵敏度。他还将研究增加SNO+接受主闪烁体体积以外的中微子事件的策略，这将涉及详细的模拟和复杂光学探测器领域的新型重建技术的开发。作为这项研究的一部分，他将研究是否有可能从至少一些这些主要基于水的事件中提取方向信息，因为这些事件可能有助于定位超新星的方向-通过全球超新星中微子早期预警系统（SNEWS）网络尽快将重要信息传递给天文观测者社区。休伊特先生还将研究一系列暗物质模型对观测到的超新星中微子的时间和能量谱以及探测器中其他相关能量沉积的影响。了解这些效应将进一步为SNO+和其他中微子实验提供信息，以了解在银河系超新星事件中可能观察到的不同现象的范围，并提高SNEWS为随后的实时观测提供及时，可靠，相关信息的能力，以及与电磁和引力“信使”的相关性。