论文标题
高清气体时间投影室中的后坐力识别的可观察物
Observables for Recoil Identification in High-Definition Gas Time Projection Chambers
论文作者
论文摘要
在核物理和粒子物理学中，核后坐力的定向检测是广泛的。在低后坐力的能量下，该能力可用于确认暗物质信号的宇宙学起源，以穿透所谓的中微子地板或区分不同的中微子来源。如果读出粒度足够高，则气体时间投影室（TPC）可以实现定向后坐力检测，就像使用微图案气态检测器（MPGD）一样。此类探测器中的一个主要挑战是识别和拒绝背景电子后坐力事件，这是由探测器材料和环境中放射性污染物引起的γ射线引起的。我们根据模拟电离的拓扑结构定义了可以区分电子和核后圈的新可观测物，即使在KEV尺度的能量下也可以区分电子和核后坐力。我们执行了一项模拟研究，该研究表明这些可观察到的东西的表现优于传统上使用的判别de/dx，最多要多达三个数量级。此外，这些新的可观测物在电离能量远低于10 keV的电离能量，即使在方向性失败的状态下也保持强劲。
Directional detection of nuclear recoils is broadly desirable in nuclear and particle physics. At low recoil energies, this capability may be used to confirm the cosmological origin of a dark matter signal, to penetrate the so-called neutrino floor, or to distinguish between different neutrino sources. Gas Time Projection Chambers (TPCs) can enable directional recoil detection if the readout granularity is sufficiently high, as is the case when micro-pattern gaseous detectors (MPGDs) are utilized. A key challenge in such detectors is identifying and rejecting background electron recoil events caused by gamma rays from radioactive contaminants in the detector materials and the environment. We define new observables that can distinguish electron and nuclear recoils, even at keV-scale energies, based on the simulated ionization's topology. We perform a simulation study that shows these observables outperform the traditionally used discriminant, dE/dx, by up to three orders of magnitude. Furthermore, these new observables work well even at ionization energies well below 10 keV and remain robust even in the regime where directionality fails.
