The PA-Supported Neutrino Program at MIT

埋藏在南极冰盖深处的冰立方中微子天文台(ICNO)是世界上最大、最灵敏的高能中微子望远镜。它是一个10亿吨重的探测器，使用南极冰层作为高能大气和天体物理中微子的探测介质。冰立方观测到的大多数中微子的能量都在大气中微子的预期范围内，这些中微子是由来自银河系附近扇区的宇宙射线在大范围的空气骤雨中产生的粒子衰变而产生的。这些可以用来测量中微子的基本性质。在较高能量下，天体物理中微子是研究高能宇宙的关键探测器。由于其独特的性质，中微子甚至可以逃脱密集区域，不受银河系或银河系外磁场的偏转，畅通无阻地穿越充满光子的宇宙。因此，中微子提供了关于可能是高能宇宙射线起源的强大宇宙物体的动力学和内部的直接信息，这些物体包括超新星、黑洞、脉冲星、活动星系核和其他极端的河外现象。该奖项使该小组能够解决以下问题：具有全球竞争力的STEM劳动力的发展；女性和少数族裔参与的增加；教师发展的改善；本科教育的改善；公众科学素养的提高；以及公众福祉。这项工作从研究中产生了有价值的副产品，包括与反应堆监测相关的反应堆通量研究，以及与医用同位素生产相关的回旋加速器开发。该小组的动机是寻找中微子领域表现出来的新物理。“新物理学”指的是超越中微子质量和三活性混合的发现，这两个发现已经得到了很好的证实。引入稀薄中微子扩展了质量态的数量，并扩展了混合矩阵。这可能会导致质量平方分裂的振荡，这种分裂异常地大。该小组将在两个项目中探索这个问题，正在进行的IceCube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.