Advanced Event Reconstruction and the Study of Prompt Muons in Ultrahigh Energy Extensive Air Showers in IceCube

冰立方中微子观测站发现了能量在20 TeV到10 PeV之间的高能中微子的外星成分，但它们的具体来源仍未确定。为了更好地了解这些中微子的大气和天体物理性质，对相应能量区域的大气μ子和中微子进行精确建模是重中之重。在一个相关的领域，在过去的几十年里，已经有了关于银河宇宙射线的起源和传播的发现。一个关键问题涉及到以超高能量向河外起源的宇宙射线的过渡。要回答这个问题，需要对10^15 eV （PeV）和10^18 eV （EeV）之间的宇宙射线初级粒子的能量和质量组成进行可靠的测量。该小组将根据冰立方天文台获得的数据，开发新的分析方法，以更好地确定这些高能粒子的能量和方向。这个项目的更广泛影响将是教育和协同。该奖项将为研究生提供资金支持和一些旅行。冰立方的表面阵列“冰顶”为研究整个银河系到河外过渡区的宇宙射线以及由此产生的大气μ子和中微子提供了独特的数据。该奖项的目标是：——用一种新的分析技术研究超高能量广泛空气簇射（EASs）中的提示μ子。与其他方法相比，该技术具有提示μ子特征对宇宙射线主粒子质量组成不敏感的独特优点；——在一种新改进的重构算法中表征了超高能EAS锋面中粒子的时间残余波动及其与角分辨率的关系，解决了IceTop高能EAS方向重构中长期存在的问题；——研发了一种统一的三维重构，直接从IceTop和InIce的重合数据中提取宇宙射线的初级质量和能量。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The IceCube Neutrino Observatory has discovered an extraterrestrial component of high-energy neutrinos in the energy range between 20 TeV and 10 PeV, yet their specific sources remain unidentified. To better understand the atmospheric and astrophysical nature of these neutrinos, precise modeling of atmospheric muons and neutrinos in the corresponding energy region is among the top priorities. In a related field, there have been discoveries regarding the origin and propagation of Galactic cosmic rays in past decades. One key question concerns the transition to cosmic rays of extragalactic origin at ultrahigh energies. Answering this question requires reliable measurements of both the energy and mass composition of cosmic ray primary particles between 10^15 eV (PeV) and 10^18 eV (EeV). This group will develop new analysis methods for better determining the energies and directions of these very high energy particles based on the data obtained from the IceCube Observatory. The broader impacts of this project will be both educational and synergistic. This award will provide funds for the support of a graduate student and some travel.With its surface array IceTop, IceCube provides unique data for the study of cosmic rays in the entire Galactic to extragalactic transition region and the atmospheric muons and neutrinos induced by them. The goals of this award are:--The study of prompt muons in ultrahigh energy extensive air showers (EASs) with a new analysis technique. Comparing to other approaches, this technique has the unique advantage that the prompt muon signature is insensitive to the cosmic ray primary particle mass composition;--Characterization of the time residual fluctuation of particles in the ultrahigh energy EAS front and its relation to the angular resolution in a newly improved reconstruction algorithm that solved a long-standing problem in high energy EAS direction reconstruction in IceTop;--R&D toward a unified 3-dimensional reconstruction that derives cosmic ray primary mass and energy directly from IceTop and InIce coincident data.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.