High Energy Neutrino Astrophysics with IceCube

这项工作的智力价值在于它测量了宇宙中高能中微子的产生，并测试了粒子物理的标准模型，从而增加了我们对高能宇宙的基础知识。最高能量宇宙射线的起源是现代物理学中最引人注目的谜团之一。空气簇射探测器已经观测到能量高达3x10^20电子伏特(EV)的事件。然而，尽管进行了几十年的工作，它们的来源、核成分和加速机制仍然未知。一些可能的来源包括活动星系核、伽马射线爆发和/或超新星遗迹。对天体物理中微子的观察将告诉我们，强子必须在这些源中加速；中微子的流量和光谱将显著限制理论模型。该奖项将支持利用最近完成的冰立方探测器的数据，搜索在这些宇宙加速器中产生的中微子的扩散通量。这项工作将在两个方面进行。第一个是寻找弥散的电子中微子和tau中微子。该小组已经展示了使用外部弦和冰立方的顶部和底部来否决进入Muon轨迹的力量，方法是使用它来测量从50千兆电子伏特(GeV)到10太电子伏特(TeV)的大气电子中微子通量。他们将把这项技术扩展到能量从10TeV到~1PetaElectronVolt(PeV)的中微子。他们还将通过其独特的拓扑结构--两个独立的级联--来搜索高能tau中微子的扩散流。其次，他们将使用这些中微子来测量能量在50TeV左右的中微子-核子截面-通过测量地球上的中微子吸收。更广泛的影响：对地外中微子的观测将对天体物理学具有广泛的意义。对宇宙中强子加速器的观测将回答国家研究委员会关于宇宙物理的研究中提出的11个问题之一：“超高能粒子来自哪里”教育和推广部分将通过在小学到高中的演讲和公共讲座向学生和普通公众传达这一前沿研究。

The intellectual merit of this work is that it measures high-energy neutrino production in the universe and tests the standard model of particle physics thus increasing our fundamental knowledge of the high-energy universe. The origin of the highest energy cosmic-rays is one of the most compelling mysteries in modern physics. Air shower detectors have observed events with energies up to 3x10^20 electron volt (eV). However, despite decades of work, their sources, nuclear composition and acceleration mechanisms remain unknown. Some possible sources include active galactic nuclei, gamma-ray bursters, and/or supernova remnants. Observation of astrophysical neutrinos will tell us that hadrons must be accelerated in these sources; the neutrino flux and spectrum will significantly constrain theoretical models. This award will support a search for the diffuse flux of neutrinos produced in these cosmic accelerators, using data from the recently completed IceCube detector. The work will be in two areas. The first is to search for a diffuse flux of electron and tau neutrinos. The group has demonstrated the power of using the outer strings and the top and bottom of IceCube to veto entering muon tracks by using it to measure the atmospheric electron neutrino flux from 50 gigaelectronvolt (GeV) to 10 teraelectronvolt (TeV). They will extend this technique to neutrinos with energies from 10 TeV up to ~ 1 petaelectronvolt (PeV). They will also search for a diffuse flux of high-energy tau neutrinos, through their distinctive topology - two separated cascades. Second, they will use these neutrinos to make a measurement of the neutrino-nucleon cross-section at an energy around 50 TeV - by measuring neutrino absorption in the Earth. Broader Impacts: The observation of extra-terrestrial neutrinos will have broad significance for astrophysics. The observation of hadronic accelerators in the universe would answer one of the 11 questions posed in the National Research Council study on the Physics of the Universe: "Where do ultra-high energy particles come from" The Education and Outreach component will communicate this forefront research to students and the general public, through presentations at elementary through high schools and public lectures.