WoU-MMA: Cosmic-Ray Physics with IceCube

该奖项为六个美国机构(其中三个在EPSCoR管辖范围内)的科学家提供资金，以对位于美国阿蒙森-斯科特南极站的冰立方中微子天文台的宇宙射线数据进行科学分析。冰立方探测器的特点是1立方公里的天然冰(深度从1.4到2.4公里)已经被改造成一个巨大的粒子探测器。与之相辅相成的是一个由162个粒子探测器组成的表面阵列，称为冰顶。冰中阵列和表面阵列都能探测到高能宇宙射线撞击大气层时引发的粒子级联产生的超短光闪烁。作为冰立方作为中微子观测站的主要任务的补充，这一世界独一无二的设置使科学进步能够理解最高能量的银河系宇宙射线的起源和大气级联中的粒子物理。除了旨在宇宙线物理方面取得根本性进展的研究外，该奖项还通过冰立方的宇宙线测量支持更广泛的科学影响，如日光层、太阳和大气科学，因为平流层和太阳事件会影响冰立方测量的宇宙线通量。因此，该奖项阐述并推进了美国国家科学基金会“宇宙之窗：多信使天体物理时代”计划以及极地计划的科学目标和目标。神秘的南极环境和引人入胜的冰立方科学是一个诱人的组合。除了在报纸和科普出版物上广泛报道外，冰立方在社交媒体和万维网上也有重要的存在。通过成功的高中大师班以及学生对科学研究的参与，该项目有助于培养多样化的STEM劳动力。冰立方中微子天文台的三维布局，冰顶表面阵列位于立方公里深的光学网格之上，也是宇宙射线空气簇射的优秀探测器。冰立方表面的电磁粒子和低能量介子，以及深冰网中TeV到PeV的介子的结合，使冰立方成为世界上独一无二的仪器，可以探测最高能量的银河宇宙射线。作为对冰立方多用途探测器任务的补充，这一装置被用来测量宇宙射线的能谱和组成，在这个能量范围内，银河系和银河系外的宇宙射线之间仍然神秘的转换被推定发生。冰立方还提供了对南半球从TeV到PeV能量的鲜为人知的宇宙线各向异性的第一次也是世界上最灵敏的测量。结合墨西哥HAWC伽马射线观测站的数据，冰立方还汇编了第一次在10TeV的全天空宇宙线各向异性观测。提供更高能量下的联合观测以及与LHAASO等其他实验相结合的计划正在进行中。冰立方还在仔细研究空气簇射中粒子物理的强子相互作用模型，特别是轻子的正向产生方面发挥了主导作用。通过这一点，冰立方将有助于理解Muon之谜，即空气簇射中测量的Muon含量与最先进的强子相互作用模型预测的Muon含量之间的不匹配。为了继续保持冰立方在这一宇宙射线物理能量范围内的领先地位，将在分析方面进行一些改进，以提高我们数据的统计数据和准确性。统计数据的显著增加是由于完整探测器的额外数据收集时间，但也是因为扩展了可分析数据相空间，以包括未包含和更倾向的事件。将开发应用机器学习技术的新事件重建，并将其用于分析表层和深层信号。更高的精确度也将通过实施更好的模型来解释冰顶水箱上的降雪，以及与原型增强的地面仪器进行交叉检查。这些改进将通过提供更高的灵敏度和分辨率来推动IceCube的宇宙射线任务，它们为继续IceCube对理解最高能量银河系宇宙线的物理和起源做出的贡献提供了一条途径。该项目由MPS物理部的IceCube研究支持和粒子天体物理-宇宙现象计划、GEO极地计划办公室的南极天体物理和地球空间科学计划、刺激竞争研究的既定计划(EPSCoR)、这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This award provides funding for scientists at six U.S. institutions (three of them in EPSCoR jurisdictions) to perform scientific analysis of cosmic-ray data from the IceCube Neutrino Observatory located at the U.S. Amundsen-Scott South Pole Station. The IceCube detector features one cubic kilometer of natural ice (at the depth from 1.4 to 2.4 km) that has been transformed into a giant particle detector. This is complemented by a surface array of 162 particle detectors called IceTop. Both the in-ice and surface array detect ultra-short light flashes from particle cascades initiated when high-energy cosmic rays hit the atmosphere. Complementary to IceCube’s main mission as a neutrino observatory, this world-unique setup enables scientific progress in understanding the origin of Galactic cosmic rays of highest energies and the particle physics in the atmospheric cascades. In addition to research aimed at fundamental progress in cosmic-ray physics, this award also supports scientific broader impacts through IceCube’s cosmic-ray measurements, such as heliospheric, solar, and atmospheric science, since stratospheric and solar events can impact the cosmic-ray flux measured by IceCube. Thus, this award addresses and advances the science objectives and goals of NSF's "Windows on the Universe: The Era of Multi-Messenger Astrophysics" program as well as those of the Polar program. The mystique of the South Pole environment and the compelling science of IceCube are an alluring mix. Besides its extensive coverage in newspapers and publications popularizing science, IceCube has a significant presence on social media and the World Wide Web. Through successful high school MasterClasses as well as student engagement in the scientific research, this project contributes to the education of a diverse STEM workforce. With its three-dimensional layout, the IceTop surface array above the cubic-kilometer deep optical grid, the IceCube Neutrino Observatory is also an excellent detector for cosmic-ray air showers. The combination of electromagnetic particles and low-energy muons at the surface and TeV to PeV muons by the deep in-ice grid makes IceCube a world-unique instrument for the most energetic Galactic cosmic rays. Complementing IceCube’s multimessenger mission, this setup is used to measure the cosmic-ray energy spectrum and composition in the energy range where the still-enigmatic transition between Galactic and extragalactic cosmic rays is presumed to occur. IceCube is also providing the first and world’s most sensitive measurements of little understood cosmic-ray anisotropies in the Southern Hemisphere at TeV to PeV energies. Combining data with the HAWC gamma-ray observatory in Mexico, IceCube has also compiled the first full-sky cosmic ray anisotropy observation at 10 TeV. Plans to provide combined observations at higher energies and with other experiments such as LHAASO are underway. IceCube also plays a leading role in scrutinizing hadronic interaction models of the particle physics in air showers, in particular, the forward production of leptons. By this, IceCube will contribute to the understanding of the muon puzzle, a mismatch between the measured muon content of air showers and the one predicted by state-of-the-art hadronic interaction models. To continue IceCube’s leading role in this energy range of cosmic-ray physics, a number of improvements in the analysis will be implemented to increase both the statistics and accuracy of our data. The significant increase in statistics results from additional data collection time with the complete detector, but also from expanding the analyzable data phase space to include uncontained and more inclined events. New event reconstructions applying machine-learning techniques will be developed and employed to analyze the surface and deep signals. Higher accuracy will also result from implementing a better model to account for snow on the IceTop tanks, as well as cross-checks with prototype enhanced surface instrumentation. These improvements will drive IceCube’s cosmic-ray mission by providing higher sensitivity and resolution Taken together, they provide a path to follow to continue IceCube’s contribution to understanding the physics and origin of highest energy Galactic cosmic rays.This project is jointly funded by the IceCube Research Support and Particle Astrophysics - Cosmic Phenomenon programs in MPS's Division of Physics, the Antarctic Astrophysics and Geospace Sciences program in GEO's Office of Polar Programs, the Established Program to Stimulate Competitive Research (EPSCoR), and the NSF Big Ideas: Windows on the Universe - Multimessenger Astrophysics.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.