The PA-Supported Neutrino Program at MIT

冰立方中微子天文台（ICNO）深埋在南极冰盖中，是世界上最大、最灵敏的高能中微子望远镜。它是一个10亿吨的探测器，利用南极冰作为探测高能大气和天体物理中微子的介质。冰立方观测到的大多数中微子的能量都在预期的大气中微子的能量范围内，这些中微子是由来自银河系附近部分的宇宙射线在广泛的空气阵雨中产生的粒子衰变产生的。这些可以用来测量中微子的基本性质。在更高的能量下，天体物理中微子是高能宇宙的关键探测器。由于其独特的性质，中微子甚至可以逃离密集的区域，不受星系或星系外磁场的偏转，并且可以不受阻碍地穿越充满光子的宇宙。因此，中微子提供了关于强大的宇宙物体的动力学和内部的直接信息，这些物体可能是高能宇宙射线的起源：超新星、黑洞、脉冲星、活动星系核和其他极端的河外现象。该奖项使该集团能够解决具有全球竞争力的STEM劳动力的发展问题；增加妇女和少数民族的参与；提高教师发展水平；加强本科教育；提高公众科学素养；还有公共福利。这项工作从研究中获得了宝贵的附带利益，包括与反应堆监测有关的反应堆通量研究和与医用同位素生产有关的回旋加速器开发。该小组的动机是寻找在中微子领域表现出来的新物理学。“新物理学”意味着超越中微子质量和三活性风味混合的发现，这是已经确立的。引入惰性中微子扩展了质量态的数量，扩展了混合矩阵。这可能导致振荡与平方质量分裂异常大。该小组将在两个项目中研究这个问题，正在进行的冰立方实验和未来的IsoDAR实验。

Embedded deep in the ice cap at the South Pole, the IceCube Neutrino Observatory (ICNO) is the world's largest and most sensitive high energy neutrino telescope. It is a 1 billion-ton detector using the Antarctic ice as a detection medium for high energy atmospheric and astrophysical neutrinos. Most of the neutrinos observed by IceCube exhibit energies in the range expected for atmospheric neutrinos originating from decays of particles produced in extensive air showers by cosmic rays coming from nearby sectors of the Milky Way Galaxy. These may be used to measure the fundamental properties of neutrinos. At higher energies, astrophysical neutrinos are key probes of the high-energy universe. Because of their unique properties, neutrinos escape even dense regions, are not deflected by galactic or extra-galactic magnetic fields and traverse the photon-filled universe unhindered. Thus, neutrinos provide direct information about the dynamics and interiors of the powerful cosmic objects that may be the origins of high energy cosmic rays: supernovae, black holes, pulsars, active galactic nuclei and other extreme extragalactic phenomena.This award enables the group to address the development of a globally competitive STEM workforce; increased participation of women and minorities; improved teacher development; improved undergraduate education; increased public scientific literacy; and public well-being. The work has valuable spin-offs from the research, including reactor flux studies relevant to reactor monitoring and the cyclotron development relevant to medical isotope production. The group is motivated by searches for new physics manifested in the neutrino sector. "New physics" means a step beyond the discoveries of neutrino mass and three-active-flavor mixing, which are well established. Introducing sterile neutrinos extends the number of mass states and expands the mixing matrix. This can lead to oscillations with squared mass splittings that are anomalously large. The group will pursue this question in two projects, the ongoing IceCube experiment and the future IsoDAR experiment.