标题： 冰立方中微子天文台的微弱粒子触发系统 显示英文标题

标题： The Faint Particle Trigger for the IceCube Neutrino Observatory

摘要： 为了提高对自由分数电荷粒子（FCP）产生的微弱信号的检测效率，冰立方中微子天文台开发了微弱粒子触发器（FPT）。这些 FCP 是标准模型（SM）扩展预测的。先前的冰立方分析显示，由于光子产生过程的$\text{z}^2$依赖性，在检测电荷为 e/3 的 FCP 时触发效率降低。FPT 通过在触发决策中引入一种以前未使用的命中类型——称为 SLC 命中的触发方式解决了这一不足。这些是单个孤立的命中，不在冰立方中用于触发高能信号。FPT 使用滑动时间窗口来分析命中，并利用四个裁剪去除噪声和明亮背景贡献。通过命中对的速率和方向一致性，有效地将噪声贡献减少到几 Hz。此外，通过要求触发窗口内最小比例的 SLC 命中，主导的大气μ子率的一部分被减少。与标准触发器相比，FPT 显著提高了触发效率，提高了 1.55 倍，同时使冰立方事件率增加了 1.004 倍。该触发算法于 2023 年 11 月在南极洲成功测试和部署。 显示英文摘要

摘要： The Faint Particle Trigger (FPT) was developed for the IceCube Neutrino Observatory to enhance the detection efficiency for faint signatures, produced by free Fractionally Charged Particles (FCP) predicted in several Standard Model (SM) extensions. A previous IceCube analysis has shown a reduced trigger efficiency in detecting FCP with a charge of e/3 due to the $\text{z}^2$ dependence of photon production processes. The FPT addresses this shortcoming by incorporating a so far unused hit type, so called SLC hits in the trigger decision. These are single isolated hits that are not used for triggering high energy signatures in IceCube. The FPT employs a sliding time window to analyze hits, utilizing four cuts to remove noise and bright background contributions. The noise contribution is effectively decreased to a few Hz by velocity and directional consistency of hit pairs. Furthermore a part of the dominating atmospheric muon rate is reduced, by requiring a minimum fraction of SLC hits in the trigger window. The FPT significantly improves the trigger efficiency by a factor of 1.55, compared to standard triggers, while increasing the event rate in IceCube by a factor 1.004. The trigger algorithm was tested and successfully deployed at South Pole in November 2023.