面向CYGNO/INITIUM项目方向性暗物质搜寻的放大与气体混合优化
Optimisation of amplification and gas mixture for directional Dark Matter searches with the CYGNO/INITIUM project
AI总结：
本文围绕CYGNO/INITIUM方向性暗物质探测项目，研究通过优化光产额、引入高电负性气体抑制电子云扩散，并利用统计工具评估方向性探测器在设定WIMP-核子灵敏度极限及区分不同暗物质模型方面的性能。
摘要：
天体物理和宇宙学观测表明存在超越标准模型的成分，即暗物质（DM）。最受支持的一类理论认为，暗物质由弱相互作用大质量粒子（WIMPs）组成，可能通过与标准物质的弱相互作用导致后者发生反冲而被探测到。太阳和地球相对于银河系中心的运动预计会在反冲谱中引起强烈的方向依赖性。能够测量反冲角分布特征的直接探测实验可获得广泛优势，例如能够正面宣称发现暗物质。CYGNO项目正是在这一背景下设立的，其目标是部署一个用于暗物质等稀有事件搜寻的大型方向性探测器。该探测器采用充有He:CF4气体混合物的气体时间投影室，具有分段放大级和颗粒状光学读出。本论文介绍了利用小型CYGNO原型机开展的工作，旨在在不降低空间和能量分辨率的前提下最大化光产额；以及加入高电负性气体以在向放大级漂移过程中减小电子云扩散，这对于精确测量反冲径迹的拓扑信息至关重要。此外，利用严格的统计工具分析了方向性探测器在直接暗物质搜寻背景下的潜在性能，既包括在改进WIMP-核子灵敏度极限设定方面的表现，也包括利用方向性探测器区分两种不同暗物质模型的能力。
英文摘要：
Astrophysical and cosmological observations suggest the existence of beyond standard model ingredient known as dark matter (DM). One of the most supported class of theories suggests that DM is composed of weakly interactive massive particles (WIMPs), possibly detectable via weak interaction with standard matter resulting in the recoil of the latter. The motion of the Sun and Earth with respect to the Galactic Centre is expected to induce a strong directional dependence in the recoil spectrum. Direct detection experiments capable of measuring the angular features of the recoils gain access to a wide range of advantages such as the possibility to positively claim a discovery of DM. The CYGNO project sets into this context, with the aim of deploying a large directional detector for rare event searches as DM. It exploits a gaseous time projection chamber filled with a He:CF4 gas mixture with a segmented amplification stage and granular optical readout. In this thesis, it is presented the work carried out with small CYGNO prototypes to maximise the light yield without degrading spatial and energy resolution, the addition of highly electronegative gases to induce a reduction of the electron cloud diffusion while drifting towards the amplification stage, very relevant to precisely measure the topological information of the recoil tracks. Moreover, the potential performances of directional detectors in the context of a direct DM search are analysed with the use of rigorous statistical tools both in the improvement in setting limits in the WIMP to nucleon sensitivity and in the capability of discerning two different DM models exploiting a directional detector.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
